java.lang.Object
- tech.tablesaw.columns.AbstractColumn<StringColumn,String>
- - tech.tablesaw.api.StringColumn

All Implemented Interfaces:

Iterable<String>, Comparator<String>, CategoricalColumn<String>, Column<String>, StringFilters, StringMapFunctions, StringReduceUtils, FilterSpec<Selection>, StringFilterSpec<Selection>
```
public class StringColumn
extends AbstractColumn<StringColumn,String>
implements CategoricalColumn<String>, StringFilters, StringMapFunctions, StringReduceUtils
```
A column that contains String values. They are assumed to be 'categorical' rather than free-form text, so are stored in an encoding that takes advantage of the expected repetition of string values.
Because the MISSING_VALUE for this column type is an empty string, there is little or no need for special handling of missing values in this class's methods.

Field Summary
- Fields inherited from class tech.tablesaw.columns.AbstractColumn
  DEFAULT_ARRAY_SIZE

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`StringColumn`	`addAll(List<String> stringValues)`	Add all the strings in the list to this column
`StringColumn`	`append(String value)`	Added for naming consistency with all other columns
`StringColumn`	`append(Column<String> column)`	Appends all the values in the argument to the bottom of this column and return this column
`Column<String>`	`append(Column<String> column, int row)`	Appends the value at the given row in the given column to the bottom of this column and return this column
`StringColumn`	`appendCell(String object)`	Add one element to the bottom of this column and set its value to the parsed value of the given String.
`StringColumn`	`appendCell(String object, AbstractColumnParser<?> parser)`	Add one element to the bottom of this column and set its value to the parsed value of the given String, as performed by the given parser
`StringColumn`	`appendMissing()`	Appends a missing value appropriate to the column
`StringColumn`	`appendObj(Object obj)`	Appends the given value to the bottom of this column and return this column
`byte[]`	`asBytes(int rowNumber)`	Returns the contents of the cell at rowNumber as a byte[]
`double[]`	`asDoubleArray()`
`DoubleColumn`	`asDoubleColumn()`
`List<String>`	`asList()`	Returns a List<String> representation of all the values in this column
`String[]`	`asObjectArray()`	Returns an array of objects as appropriate for my type of column
`Set<String>`	`asSet()`	Returns a Set containing all the unique values in this column
`StringColumn`	`asStringColumn()`	Returns a StringColumn consisting of the (unformatted) String representation of this column values
`List<String>`	`bottom(int n)`	Returns the smallest ("bottom") n values in the column
`int`	`byteSize()`	Returns the width of a cell in this column, in bytes.
`void`	`clear()`	Removes all elements TODO: Make this return this column
`int`	`compare(String o1, String o2)`
`boolean`	`contains(String aString)`	Returns true if this column contains a cell with the given string, and false otherwise
`StringColumn`	`copy()`	Returns a deep copy of the receiver
`Table`	`countByCategory()`	Returns a count of the number of elements in each category (i.e., the number of repetitions of each value) TODO: This needs to be well tested, especially for IntColumn
`int`	`countMissing()`	Returns the count of missing values in this column
`int`	`countOccurrences(String value)`
`int`	`countUnique()`	Returns the count of unique values in this column.
`static StringColumn`	`create(String name)`
`static StringColumn`	`create(String name, int size)`
`static StringColumn`	`create(String name, String... strings)`
`static StringColumn`	`create(String name, Collection<String> strings)`
`static StringColumn`	`create(String name, Stream<String> stream)`
`static StringColumn`	`createInternal(String name, DictionaryMap map)`
`StringColumn`	`emptyCopy()`	Returns a copy of the receiver with no data.
`StringColumn`	`emptyCopy(int rowSize)`	Returns an empty copy of the receiver, with its internal storage initialized to the given row size.
`boolean`	`equals(int rowNumber1, int rowNumber2)`	Returns true if the value in this column at rowNumber1 is equal to the value at rowNumber2
`int`	`firstIndexOf(String value)`
`String`	`get(int rowIndex)`	Returns the value at rowIndex in this column.
`DictionaryMap`	`getDictionary()`	For tablesaw internal use Note: This method returns null if the stringDataType is TEXTUAL
`double`	`getDouble(int i)`
`List<BooleanColumn>`	`getDummies()`	Returns a list of boolean columns suitable for use as dummy variables in, for example, regression analysis, select a column of categorical data must be encoded as a list of columns, such that each column represents a single category and indicates whether it is present (1) or not present (0)
`StringColumnFormatter`	`getPrintFormatter()`	Returns the current `StringColumnFormatter`.
`String`	`getString(int row)`	Returns a string representation of the value at the given row.
`String`	`getUnformattedString(int row)`	Returns a String representation of the value at index r, without any formatting applied
`boolean`	`isEmpty()`	Returns true if the column has no data
`Selection`	`isEqualTo(String string)`
`Selection`	`isIn(String... strings)`
`Selection`	`isIn(Collection<String> strings)`
`Selection`	`isMissing()`	Returns a selection containing an index for every missing value in this column
`boolean`	`isMissing(int rowNumber)`	Returns true if the value at rowNumber is missing
`Selection`	`isNotEqualTo(String string)`
`Selection`	`isNotIn(String... strings)`
`Selection`	`isNotIn(Collection<String> strings)`
`Selection`	`isNotMissing()`	Returns a selection containing an index for every non-missing value in this column
`Iterator<String>`	`iterator()`
`StringColumn`	`lag(int n)`	Returns a column of the same type and size as the receiver, containing the receivers values offset by n.
`StringColumn`	`lead(int n)`	Returns a column of the same type as the receiver, containing the receivers values offset -n For example if you lead a column containing 2, 3, 4 by 1, you get a column containing 3, 4, NA.
`StringColumn`	`removeMissing()`	Returns a copy of this column with the missing values removed
`it.unimi.dsi.fastutil.ints.IntComparator`	`rowComparator()`	Returns an IntComparator for sorting my rows
`StringColumn`	`set(int rowIndex, String stringValue)`	Sets the value at index row to the given value and return this column
`Column<String>`	`set(int row, Column<String> column, int sourceRow)`	Sets the value at row to the value at sourceRow in the given column and return this column
`StringColumn`	`set(Selection rowSelection, String newValue)`	Conditionally update this column, replacing current values with newValue for all rows where the current value matches the selection criteria
`StringColumn`	`setMissing(int i)`	Sets the value at index i to the missing-value indicator for this column type, and return this column
`void`	`setPrintFormatter(StringColumnFormatter formatter)`	Sets an `StringColumnFormatter` which will be used to format the display of data from this column when it is printed (using, for example, Table:print()) and optionally when written to a text file like a CSV.
`int`	`size()`	Returns the number of elements (a.k.a.
`void`	`sortAscending()`	Sorts my values in ascending order
`void`	`sortDescending()`	Sorts my values in descending order
`Table`	`summary()`	Returns a table containing a ColumnType specific summary of the data in this column
`List<String>`	`top(int n)`	Returns the largest ("top") n values in the column
`StringColumn`	`unique()`	Returns a new Column containing all the unique values in this column
`int`	`valueHash(int rowNumber)`	Returns an int suitable as a hash for the value in this column at the given index
`static boolean`	`valueIsMissing(String string)`
`StringColumn`	`where(Selection selection)`	Returns a new column containing the subset referenced by the `Selection`

Methods inherited from class tech.tablesaw.columns.AbstractColumn
filter, first, indexOf, inRange, last, lastIndexOf, map, max, min, name, parser, sampleN, sampleX, set, setName, setParser, sorted, subset, toString, type

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Methods inherited from interface tech.tablesaw.columns.Column
allMatch, anyMatch, columnWidth, count, count, filter, first, indexOf, inRange, interpolate, last, lastIndexOf, map, map, mapInto, max, max, min, min, name, noneMatch, parser, print, reduce, reduce, rolling, sampleN, sampleX, set, set, set, setMissingTo, setName, setParser, sorted, subset, title, type

Methods inherited from interface java.util.Comparator
equals, reversed, thenComparing, thenComparing, thenComparing, thenComparingDouble, thenComparingInt, thenComparingLong

Methods inherited from interface java.lang.Iterable
forEach, spliterator

Methods inherited from interface tech.tablesaw.columns.strings.StringFilters
containsString, endsWith, equalsIgnoreCase, equalsIgnoreCase, eval, eval, eval, eval, isAlpha, isAlphaNumeric, isEmptyString, isEqualTo, isIn, isLongerThan, isLowerCase, isNotEqualTo, isNotIn, isNumeric, isShorterThan, isUpperCase, lengthEquals, matchesRegex, startsWith, startsWith

Methods inherited from interface tech.tablesaw.columns.strings.StringMapFunctions
abbreviate, capitalize, commonPrefix, commonSuffix, concatenate, concatenate, countTokens, distance, format, join, length, lowerCase, name, padEnd, padStart, parseDouble, parseFloat, parseInt, repeat, replaceAll, replaceAll, replaceFirst, substring, substring, tokenizeAndRemoveDuplicates, tokenizeAndSort, tokenizeAndSort, tokens, trim, uniqueTokens, upperCase

Methods inherited from interface tech.tablesaw.columns.strings.StringReduceUtils
appendAll, appendAll

- Method Detail
  - valueIsMissing
```
public static boolean valueIsMissing(String string)
```
  - appendMissing
```
public StringColumn appendMissing()
```
    Appends a missing value appropriate to the column
    
    Specified by:
    
    appendMissing in interface Column<String>
  - valueHash
```
public int valueHash(int rowNumber)
```
    Returns an int suitable as a hash for the value in this column at the given index
    
    Specified by:
    
    valueHash in interface Column<String>
  - equals
```
public boolean equals(int rowNumber1,
                      int rowNumber2)
```
    Returns true if the value in this column at rowNumber1 is equal to the value at rowNumber2
    
    Specified by:
    
    equals in interface Column<String>
  - create
```
public static StringColumn create(String name)
```
  - create
```
public static StringColumn create(String name,
                                  String... strings)
```
  - create
```
public static StringColumn create(String name,
                                  Collection<String> strings)
```
  - createInternal
```
public static StringColumn createInternal(String name,
                                          DictionaryMap map)
```
  - create
```
public static StringColumn create(String name,
                                  int size)
```
  - create
```
public static StringColumn create(String name,
                                  Stream<String> stream)
```
  - setPrintFormatter
```
public void setPrintFormatter(StringColumnFormatter formatter)
```
    Sets an StringColumnFormatter which will be used to format the display of data from this column when it is printed (using, for example, Table:print()) and optionally when written to a text file like a CSV.
  - getPrintFormatter
```
public StringColumnFormatter getPrintFormatter()
```
    Returns the current StringColumnFormatter.
  - isMissing
```
public boolean isMissing(int rowNumber)
```
    Returns true if the value at rowNumber is missing
    
    Specified by:
    
    isMissing in interface Column<String>
  - emptyCopy
```
public StringColumn emptyCopy()
```
    Returns a copy of the receiver with no data. The column name and type are the same.
    
    Specified by:
    
    emptyCopy in interface Column<String>
    
    Specified by:
    
    emptyCopy in class AbstractColumn<StringColumn,String>
    
    Returns:
    
    a empty copy of Column
  - emptyCopy
```
public StringColumn emptyCopy(int rowSize)
```
    Returns an empty copy of the receiver, with its internal storage initialized to the given row size.
    
    Specified by:
    
    emptyCopy in interface Column<String>
    
    Parameters:
    
    rowSize - the initial row size
    
    Returns:
    
    a Column
  - sortAscending
```
public void sortAscending()
```
    Sorts my values in ascending order
    
    Specified by:
    
    sortAscending in interface Column<String>
  - sortDescending
```
public void sortDescending()
```
    Sorts my values in descending order
    
    Specified by:
    
    sortDescending in interface Column<String>
  - size
```
public int size()
```
    Returns the number of elements (a.k.a. rows or cells) in the column
    
    Specified by:
    
    size in interface Column<String>
    
    Specified by:
    
    size in interface StringFilters
    
    Specified by:
    
    size in interface StringMapFunctions
    
    Specified by:
    
    size in interface StringReduceUtils
    
    Returns:
    
    size as int
  - get
```
public String get(int rowIndex)
```
    Returns the value at rowIndex in this column. The index is zero-based.
    
    Specified by:
    
    get in interface Column<String>
    
    Specified by:
    
    get in interface StringFilters
    
    Parameters:
    
    rowIndex - index of the row
    
    Returns:
    
    value as String
    
    Throws:
    
    IndexOutOfBoundsException - if the given rowIndex is not in the column
  - asList
```
public List<String> asList()
```
    Returns a List<String> representation of all the values in this column
    NOTE: Unless you really need a string consider using the column itself for large datasets as it uses much less memory
    
    Specified by:
    
    asList in interface Column<String>
    
    Returns:
    
    values as a list of String.
  - summary
```
public Table summary()
```
    Returns a table containing a ColumnType specific summary of the data in this column
    
    Specified by:
    
    summary in interface Column<String>
  - countByCategory
```
public Table countByCategory()
```
    Returns a count of the number of elements in each category (i.e., the number of repetitions of each value) TODO: This needs to be well tested, especially for IntColumn
    
    Specified by:
    
    countByCategory in interface CategoricalColumn<String>
  - clear
```
public void clear()
```
    Removes all elements TODO: Make this return this column
    
    Specified by:
    
    clear in interface Column<String>
  - lead
```
public StringColumn lead(int n)
```
    Returns a column of the same type as the receiver, containing the receivers values offset -n For example if you lead a column containing 2, 3, 4 by 1, you get a column containing 3, 4, NA.
    
    Specified by:
    
    lead in interface Column<String>
  - lag
```
public StringColumn lag(int n)
```
    Returns a column of the same type and size as the receiver, containing the receivers values offset by n.
    For example if you lag a column containing 2, 3, 4 by 1, you get a column containing NA, 2, 3
    
    Specified by:
    
    lag in interface Column<String>
  - set
```
public StringColumn set(Selection rowSelection,
                        String newValue)
```
    Conditionally update this column, replacing current values with newValue for all rows where the current value matches the selection criteria
    Examples: myCatColumn.set(myCatColumn.isEqualTo("Cat"), "Dog"); // no more cats myCatColumn.set(myCatColumn.valueIsMissing(), "Fox"); // no more missing values
    
    Specified by:
    
    set in interface Column<String>
    
    Overrides:
    
    set in class AbstractColumn<StringColumn,String>
  - set
```
public StringColumn set(int rowIndex,
                        String stringValue)
```
    Sets the value at index row to the given value and return this column
    
    Specified by:
    
    set in interface Column<String>
  - countUnique
```
public int countUnique()
```
    Returns the count of unique values in this column.
    
    Specified by:
    
    countUnique in interface Column<String>
    
    Returns:
    
    unique values as int
  - contains
```
public boolean contains(String aString)
```
    Returns true if this column contains a cell with the given string, and false otherwise
    
    Specified by:
    
    contains in interface Column<String>
    
    Parameters:
    
    aString - the value to look for
    
    Returns:
    
    true if contains, false otherwise
  - setMissing
```
public StringColumn setMissing(int i)
```
    Sets the value at index i to the missing-value indicator for this column type, and return this column
    
    Specified by:
    
    setMissing in interface Column<String>
  - addAll
```
public StringColumn addAll(List<String> stringValues)
```
    Add all the strings in the list to this column
    
    Parameters:
    
    stringValues - a list of values
  - appendCell
```
public StringColumn appendCell(String object)
```
    Add one element to the bottom of this column and set its value to the parsed value of the given String. Parsing is type-specific
    
    Specified by:
    
    appendCell in interface Column<String>
  - appendCell
```
public StringColumn appendCell(String object,
                               AbstractColumnParser<?> parser)
```
    Add one element to the bottom of this column and set its value to the parsed value of the given String, as performed by the given parser
    
    Specified by:
    
    appendCell in interface Column<String>
  - rowComparator
```
public it.unimi.dsi.fastutil.ints.IntComparator rowComparator()
```
    Returns an IntComparator for sorting my rows
    
    Specified by:
    
    rowComparator in interface Column<String>
  - isMissing
```
public Selection isMissing()
```
    Description copied from interface: Column
    
    Returns a selection containing an index for every missing value in this column
    
    Specified by:
    
    isMissing in interface Column<String>
    
    Specified by:
    
    isMissing in interface FilterSpec<Selection>
    
    Specified by:
    
    isMissing in interface StringFilters
  - isNotMissing
```
public Selection isNotMissing()
```
    Description copied from interface: Column
    
    Returns a selection containing an index for every non-missing value in this column
    
    Specified by:
    
    isNotMissing in interface Column<String>
    
    Specified by:
    
    isNotMissing in interface FilterSpec<Selection>
    
    Specified by:
    
    isNotMissing in interface StringFilters
  - isEmpty
```
public boolean isEmpty()
```
    Returns true if the column has no data
    
    Specified by:
    
    isEmpty in interface Column<String>
    
    Returns:
    
    true if empty, false if not
  - isEqualTo
```
public Selection isEqualTo(String string)
```
    Specified by:
    
    isEqualTo in interface StringFilters
    
    Specified by:
    
    isEqualTo in interface StringFilterSpec<Selection>
  - isNotEqualTo
```
public Selection isNotEqualTo(String string)
```
    Specified by:
    
    isNotEqualTo in interface StringFilters
    
    Specified by:
    
    isNotEqualTo in interface StringFilterSpec<Selection>
  - getDummies
```
public List<BooleanColumn> getDummies()
```
    Returns a list of boolean columns suitable for use as dummy variables in, for example, regression analysis, select a column of categorical data must be encoded as a list of columns, such that each column represents a single category and indicates whether it is present (1) or not present (0)
    
    Returns:
    
    a list of BooleanColumn
  - unique
```
public StringColumn unique()
```
    Returns a new Column containing all the unique values in this column
    
    Specified by:
    
    unique in interface Column<String>
    
    Returns:
    
    a column with unique values.
  - asDoubleColumn
```
public DoubleColumn asDoubleColumn()
```
  - where
```
public StringColumn where(Selection selection)
```
    Returns a new column containing the subset referenced by the Selection
    
    Specified by:
    
    where in interface Column<String>
  - copy
```
public StringColumn copy()
```
    Returns a deep copy of the receiver
    
    Specified by:
    
    copy in interface Column<String>
    
    Returns:
    
    a Column
  - append
```
public StringColumn append(Column<String> column)
```
    Appends all the values in the argument to the bottom of this column and return this column
    
    Specified by:
    
    append in interface Column<String>
  - countMissing
```
public int countMissing()
```
    Returns the count of missing values in this column
    
    Specified by:
    
    countMissing in interface Column<String>
    
    Returns:
    
    missing values as int
  - removeMissing
```
public StringColumn removeMissing()
```
    Returns a copy of this column with the missing values removed
    
    Specified by:
    
    removeMissing in interface Column<String>
  - iterator
```
public Iterator<String> iterator()
```
    Specified by:
    
    iterator in interface Iterable<String>
  - asSet
```
public Set<String> asSet()
```
    Description copied from interface: Column
    
    Returns a Set containing all the unique values in this column
    
    Specified by:
    
    asSet in interface Column<String>
  - asBytes
```
public byte[] asBytes(int rowNumber)
```
    Returns the contents of the cell at rowNumber as a byte[]
    
    Specified by:
    
    asBytes in interface Column<String>
    
    Parameters:
    
    rowNumber - index of the row
    
    Returns:
    
    content as byte[]
  - getDouble
```
public double getDouble(int i)
```
  - asDoubleArray
```
public double[] asDoubleArray()
```
  - append
```
public StringColumn append(String value)
```
    Added for naming consistency with all other columns
    
    Specified by:
    
    append in interface Column<String>
  - appendObj
```
public StringColumn appendObj(Object obj)
```
    Appends the given value to the bottom of this column and return this column
    
    Specified by:
    
    appendObj in interface Column<String>
  - isIn
```
public Selection isIn(String... strings)
```
    Specified by:
    
    isIn in interface StringFilters
    
    Specified by:
    
    isIn in interface StringFilterSpec<Selection>
  - isIn
```
public Selection isIn(Collection<String> strings)
```
    Specified by:
    
    isIn in interface StringFilters
    
    Specified by:
    
    isIn in interface StringFilterSpec<Selection>
  - isNotIn
```
public Selection isNotIn(String... strings)
```
    Specified by:
    
    isNotIn in interface StringFilters
    
    Specified by:
    
    isNotIn in interface StringFilterSpec<Selection>
  - isNotIn
```
public Selection isNotIn(Collection<String> strings)
```
    Specified by:
    
    isNotIn in interface StringFilters
    
    Specified by:
    
    isNotIn in interface StringFilterSpec<Selection>
  - firstIndexOf
```
public int firstIndexOf(String value)
```
  - countOccurrences
```
public int countOccurrences(String value)
```
  - asObjectArray
```
public String[] asObjectArray()
```
    Returns an array of objects as appropriate for my type of column
    
    Specified by:
    
    asObjectArray in interface Column<String>
  - asStringColumn
```
public StringColumn asStringColumn()
```
    Returns a StringColumn consisting of the (unformatted) String representation of this column values
    
    Specified by:
    
    asStringColumn in interface Column<String>
    
    Overrides:
    
    asStringColumn in class AbstractColumn<StringColumn,String>
    
    Returns:
    
    a StringColumn built using the column Column.getUnformattedString(int) method
  - getDictionary
```
@Nullable
public DictionaryMap getDictionary()
```
    For tablesaw internal use Note: This method returns null if the stringDataType is TEXTUAL
  - getString
```
public String getString(int row)
```
    Returns a string representation of the value at the given row.
    
    Specified by:
    
    getString in interface Column<String>
    
    Specified by:
    
    getString in interface StringMapFunctions
    
    Parameters:
    
    row - The index of the row.
    
    Returns:
    
    value as String
  - getUnformattedString
```
public String getUnformattedString(int row)
```
    Returns a String representation of the value at index r, without any formatting applied
    
    Specified by:
    
    getUnformattedString in interface Column<String>
  - top
```
public List<String> top(int n)
```
    Returns the largest ("top") n values in the column
    
    Parameters:
    
    n - The maximum number of records to return. The actual number will be smaller if n is greater than the number of observations in the column
    
    Returns:
    
    A list, possibly empty, of the largest observations
  - bottom
```
public List<String> bottom(int n)
```
    Returns the smallest ("bottom") n values in the column
    
    Parameters:
    
    n - The maximum number of records to return. The actual number will be smaller if n is greater than the number of observations in the column
    
    Returns:
    
    A list, possibly empty, of the smallest n observations
  - append
```
public Column<String> append(Column<String> column,
                             int row)
```
    Appends the value at the given row in the given column to the bottom of this column and return this column
    
    Specified by:
    
    append in interface Column<String>
  - set
```
public Column<String> set(int row,
                          Column<String> column,
                          int sourceRow)
```
    Sets the value at row to the value at sourceRow in the given column and return this column
    
    Specified by:
    
    set in interface Column<String>
  - byteSize
```
public int byteSize()
```
    Returns the width of a cell in this column, in bytes.
    
    Specified by:
    
    byteSize in interface Column<String>
    
    Returns:
    
    width in bytes
  - compare
```
public int compare(String o1,
                   String o2)
```
    Specified by:
    
    compare in interface Comparator<String>

Class StringColumn

Field Summary

Fields inherited from class tech.tablesaw.columns.AbstractColumn

Method Summary

Methods inherited from class tech.tablesaw.columns.AbstractColumn

Methods inherited from class java.lang.Object

Methods inherited from interface tech.tablesaw.columns.Column

Methods inherited from interface java.util.Comparator

Methods inherited from interface java.lang.Iterable

Methods inherited from interface tech.tablesaw.columns.strings.StringFilters

Methods inherited from interface tech.tablesaw.columns.strings.StringMapFunctions

Methods inherited from interface tech.tablesaw.columns.strings.StringReduceUtils

Method Detail

valueIsMissing

appendMissing

valueHash

equals

create

create

create

createInternal

create

create

setPrintFormatter

getPrintFormatter

isMissing

emptyCopy

emptyCopy

sortAscending

sortDescending

size

get

asList

summary

countByCategory

clear

lead

lag

set

set

countUnique

contains

setMissing

addAll

appendCell

appendCell

rowComparator

isMissing

isNotMissing

isEmpty

isEqualTo

isNotEqualTo

getDummies

unique

asDoubleColumn

where

copy

append

countMissing

removeMissing

iterator

asSet

asBytes

getDouble

asDoubleArray

append

appendObj

isIn

isIn

isNotIn

isNotIn

firstIndexOf

countOccurrences

asObjectArray

asStringColumn

getDictionary

getString

getUnformattedString

top

bottom