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public final class java.lang.String
extends java.lang.Object
{
// Constructors
public String();
public String(byte ascii[], int hibyte);
public String(byte ascii[], int hibyte,
int offset, int count);
public String(char value[]);
public String(char value[], int offset, int count);
public String(String value);
public String(StringBuffer buffer);
// Methods
public char charAt(int index);
public int compareTo(String anotherString);
public String concat(String str);
public static String copyValueOf(char data[]);
public static String
copyValueOf(char data[], int offset, int count);
public boolean endsWith(String suffix);
public boolean equals(Object anObject);
public boolean equalsIgnoreCase(String anotherString);
public void getBytes(int srcBegin, int srcEnd,
byte dst[], int dstBegin);
public void getChars(int srcBegin, int srcEnd,
char dst[], int dstBegin);
public int hashCode();
public int indexOf(int ch);
public int indexOf(int ch, int fromIndex);
public int indexOf(String str);
public int indexOf(String str, int fromIndex);
public String intern();
public int lastIndexOf(int ch);
public int lastIndexOf(int ch, int fromIndex);
public int lastIndexOf(String str);
public int lastIndexOf(String str, int fromIndex);
public int length();
public boolean regionMatches(boolean ignoreCase,
int toffset, String other, int ooffset, int len);
public boolean regionMatches(int toffset, String other,
int ooffset, int len);
public String replace(char oldChar,
char newChar);
public boolean startsWith(String prefix);
public boolean startsWith(String prefix, int toffset);
public String substring(int beginIndex);
public String substring(int beginIndex, int endIndex);
public char[] toCharArray();
public String toLowerCase();
public String toString();
public String toUpperCase();
public String trim();
public static String valueOf(boolean b);
public static String valueOf(char c);
public static String valueOf(char data[]);
public static String
valueOf(char data[], int offset, int count);
public static String valueOf(double d);
public static String valueOf(float f);
public static String valueOf(int i);
public static String valueOf(long l);
public static String valueOf(Object obj);
}
The String class represents character strings. All string literals in Java programs, such as "abc" are implemented as instances of this class.
Strings are constant, their values cannot be changed after they are created. String buffers support mutable strings.
The class String includes methods for examining individual characters of the sequence, for comparing strings, for searching strings, for extracting substrings, and for creating a copy of a string with all characters translated to uppercase or to lowercase.
public String()Allocates a new String containing no characters.
public String(byte ascii[], int hibyte)Allocates a new String containg characters constructed from an array of 8- bit integer values. Each character c in the resulting string is constructed from the corresponding component b in the byte array such that
c == (char)(((hibyte & 0xff) << 8) | (b & 0xff))
Parameter Description ascii the bytes to be converted to characters hibyte the top 8 bits of each 16-bit Unicode character
public String(byte ascii[], int hibyte, int offset, int count)Allocates a new String constructed from a subarray of an array of 8-bit integer values.
The offset argument is the index of the first byte of the subarray, and the count argument specifies the length of the subarray.
Each byte in the subarray is converted to a char as specified in the method above .
Parameter Description ascii the bytes to be converted to characters hibyte the top 8 bits of each 16-bit Unicode character offset the initial offset count the length Throw:
StringIndexOutOfBoundsException
If the offset or count argument is invalid.
public String(char value[])Allocates a new String so that it represents the sequence of characters currently contained in the character array argument.
Parameter Description value the initial value of the string
public String(char value[], int offset, int count)Allocates a new String that contains characters from a subarray of the character array argument. The offset argument is the index of the first character of the subarray and the count argument specifies the length of the subarray.
Parameter Description value array that is the source of characters offset the initial offset count the length Throw:
StringIndexOutOfBoundsException
If the offset and count arguments index characters outside the bounds of the value array.
public String(String value)Allocates a new string that contains the same sequence of characters as the string argument.
Parameter Description value a String.
public String(StringBuffer buffer)Allocates a new string that contains the sequence of characters currently contained in the string buffer argument.
Parameter Description buffer a StringBuffer.
public char charAt(int index)Return Value:
Returns The character at the specified index of this string. The first character is at index 0.
Parameter Description index the index of the desired character Throw:
StringIndexOutOfBoundsException
If the index is out of range.
public int compareTo(String anotherString)Compares two strings lexicographically.
Return Value:
Returns The value 0 if the argument string is equal to this string; a value less than 0 if this string is lexicographically less than the string argument; and a value greater than 0 if this string is lexicographically greater than the string argument.
Parameter Description anotherString the String to be compared
public String concat(String str)Concatenates the string argument to the end of this string.
If the length of the argument string is zero, then this object is returned.
Return Value:
Returns A string that represents the concatenation of this object's characters followed by the string argument's characters.
Parameter Description str the String which is concatenated to the end of this String
public static String copyValueOf(char data[])Return Value:
Returns a String that contains the characters of the character array.
Parameter Description data the character array
public static String copyValueOf(char data[], int offset, int count)Return Value:
Returns a String that contains the characters of the specified subarray of the character array.
Parameter Description data the character array offset initial offset of the subarray count length of the subarray
public boolean endsWith(String suffix)Return Value:
Returns true if the character sequence represented by the argument is a suffix of the character sequence represented by this object; false otherwise.
Parameter Description suffix the suffix
public boolean equals(Object anObject)The result is true if and only if the argument is not null and is a String object that represents the same sequence of characters as this object.
Return Value:
Returns true if the String's are equal; false otherwise.
Parameter Description anObject the object to compare this String against Overrides:
equals in class Object .
See Also: equalsIgnoreCase
public boolean equalsIgnoreCase(String anotherString)The result is true if and only if the argument is not null and is a String object that represents the same sequence of characters as this object, where case is ignored.
Two characters are considered the same, ignoring case, if at least one of the following is true:
- The two characters are the same (as compared by the == operator).
- Applying the method Character.toUppercase to each character produces the same result.
- Applying the method Character.toLowercase to each character produces the same result.
Two sequence of characters are the same, ignoring case, if the sequences have the same length and corresponding characters are the same, ignoring case.
Return Value:
Returns true if the String's are equal, ignoring case; false otherwise.
Parameter Description anotherString the String to compare this String against
public void getBytes(int srcBegin, int srcEnd, byte dst[], int dstBegin)Copies characters from this string into the destination byte array. Each byte receives the 8 low-order bits of the corresponding character.
The first character to be copied is at index srcBegin; the last character to be copied is at index srcEnd-1. The total number of characters to be copied is srcEnd-srcBegin. The characters, converted to bytes, are copied into the subarray of dst starting at index dstBegin and ending at index:
dstbegin+(srcEnd-srcBegin)-1
Parameter Description srcBegin index of the first character in the string to copy srcEnd index after the last character in the string to copy dst the destination array dstBegin the start offset in the destination array
public void getChars(int srcBegin, int srcEnd, char dst[], int dstBegin)Copies characters from this string into the destination character array.
The first character to be copied is at index srcBegin; the last character to be copied is at index srcEnd-1 (thus the total number of characters to be copied is srcEnd-srcBegin). The characters are copied into the subarray of dst starting at index dstBegin and ending at index:
dstbegin+(srcEnd-srcBegin)-1
Parameter Description srcBegin index of the first character in the string to copy srcEnd index after the last character in the string to copy dst the destination array dstBegin the start offset in the destination array
public int hashCode()Return Value:
Returns a hash code value for this object.
Overrides:
hashCode in class Object .
public int indexOf(int ch)Return Value:
Returns the index of the first occurrence of the character in the character sequence represented by this object, or -1 if the character does not occur.
Parameter Description ch a character
public int indexOf(int ch, int fromIndex)Return Value:
Returns the index of the first occurrence of the character in the character sequence represented by this object that is greater than or equal to fromIndex, or -1 if the character does not occur.
Parameter Description ch a character fromIndex the index to start the search from
public int indexOf(String str)Return Value:
Returns if the string argument occurs as a substring within this object, then the index of the first character of the first such substring is returned; if it does not occur as a substring, -1 is returned.
Parameter Description str any string
public int indexOf(String str, int fromIndex)Return Value:
Returns If the string argument occurs as a substring within this object at a starting index no smaller than fromIndex then the index of the first character of the first such substring is returned. If it does not occur as a substring starting at fromIndex or beyond, -1 is returned.
Parameter Description str the substring to search for fromIndex the index to start the search from
public String intern()Creates a canonical representation for the string object.
If s and t are strings such that s.equals(t), it is guaranteed that s.intern() == t.intern().
Return Value:
Returns a string that has the same contents as this string, but is guaranteed to be from a pool of unique strings.
public int lastIndexOf(int ch)Return Value:
Returns the index of the last occurrence of the character in the character sequence represented by this object, or -1 if the character does not occur.
Parameter Description ch a character.
public int lastIndexOf(int ch, int fromIndex)Return Value:
Returns the index of the last occurrence of the character in the character sequence represented by this object that is less than or equal to from-Index, or -1 if the character does not occur before that point.
Parameter Description ch a character fromIndex the index to start the search from
public int lastIndexOf(String str)Return Value:
Returns If the string argument occurs as a substring within this object, then the index of the first character of the last such substring is returned. If it does not occur as a substring, -1 is returned.
Parameter Description str the substring to search for
public int lastIndexOf(String str, int fromIndex)Return Value:
Returns If the string argument occurs as a substring within this object at a starting index no greater than fromIndex then the index of the first character of the lastsuch substring is returned. If it does not occur as a substring starting at fromIndex or earlier, -1 is returned.
Parameter Description str the substring to search for fromIndex the index to start the search from
public int length()Return Value:
Returns the length of the sequence of characters represented by this object is returned.
public boolean regionMatches(boolean ignoreCase, int toffset, String other, int ooffset, int len)Determines if two string regions are equal.
If toffset or ooffset is negative, or if toffset+length is greater than the length of this string, or if ooffset+length is greater than the length of the string argument, then this method returns false.
Return Value:
Returns true if the specified subregion of this string matches the specified subregion of the string argument; false otherwise. Whether the matching is exact or case insensitive depends on the ignoreCase argument.
Parameter Description ignoreCase if true, ignore case when comparing characters toffset starting offset of the subregion in this string other string argument ooffset starting offset of the subregion in the string argument len the number of characters to compare
public boolean regionMatches(int toffset, String other, int ooffset, int len)Determines if two string regions are equal.
If toffset or ooffset is negative, or if toffset+length is greater than the length of this string, or if ooffset+length is greater than the length of the string argument, then this method returns false.
Return Value:
Returns true if the specified subregion of this string exactly matches the specified subregion of the string argument; false otherwise.
Parameter Description toffset starting offset of the subregion in this string other string argument ooffset starting offset of the subregion in the string argument len the number of characters to compare
public String replace(char oldChar, char newChar)Returns a new string resulting from replacing all occurrences of oldChar in this string with newChar.
If the character oldChar does not occur in the character sequence represented by this object, then this string is returned.
Return Value:
Returns a string derived from this string by replacing every occurrence of oldChar with newChar.
Parameter Description oldChar the old character newChar the new character
public boolean startsWith(String prefix)Return Value:
Returns true if the character sequence represented by the argument is a prefix of the character sequence represented by this string; false otherwise
Parameter Description prefix the prefix
public boolean startsWith(String prefix, int toffset)Return Value:
Returns true if the character sequence represented by the argument is a prefix of the substring of this object starting at index toffset; false otherwise
Parameter Description prefix the prefix toffset where to begin looking in the the String
public String substring(int beginIndex)Creates a new string that is a substring of this string. The substring begins at the specified index and extends to the end of this string.
Return Value:
Returns the specified substring.
Parameter Description beginIndex the beginning index, inclusive Throw:
StringIndexOutOfBoundsException
If the beginIndex is out of range.
public String substring(int beginIndex, int endIndex)Creates a new string that is a substring of this string. The substring begins at the specified beginIndex and extends to the character at index endIndex - 1.
Return Value:
Returns the specified substring.
Parameter Description beginIndex the beginning index, inclusive endIndex the ending index, exclusive Throw:
StringIndexOutOfBoundsException
If the beginIndex or the endIndex is out of range.
public char[] toCharArray()Return Value:
Returns A newly allocated character array whose length is the length of this string and whose contents is initialized to contain the character sequence represented by this string.
public String toLowerCase()Converts a string to lowercase.
If no character in this string has a different lowercase version , then this string is returned.
Otherwise, a new string is allocated, whose length is identical to this string, and such that each character which has a difference lowercase version is mapped to this lower case equivalent.
Return Value:
Returns the string, converted to lowercase.
public String toString()This object (which is already a string!) is itself returned.
Return Value:
Returns the string itself.
Overrides:
toString in class Object .
public String toUpperCase()Converts a string to uppercase.
If no character in this string has a different uppercase version , then this string is returned.
Otherwise, a new string is allocated, whose length is identical to this string, and such that each character which has a difference uppercase version is mapped to this uppercase equivalent.
Return Value:
Returns the string, converted to uppercase.
public String trim()Removes white space from both ends of a string.
All characters that have codes less than or equal to '\u0020' (the space character) are considered to be white space.
Return Value:
Returns this string, with whitespace removed from the front and end
public static String valueOf(boolean b)Creates the string representation of the boolean argument.
Return Value:
Returns if the argument is true, a string equal to "true" is returned; otherwise, a string equal to "false" is returned.
Parameter Description b a boolean
public static String valueOf(char c)Creates the string representation of the char argument.
Return Value:
Returns a newly allocated string of length one containing as its single characer the argument c.
Parameter Description c a char
public static String valueOf(char data[])Creates the string representation of the char array argument.
Return Value:
Returns a newly allocated string representing the same sequence of characters contained in the character array argument.
Parameter Description data a char array
public static String valueOf(char data[], int offset, int count)Creates the string representation of a specific subarray of the char array argument.
The offset argument is the index of the first character of the subarray. The count argument specifies the length of the subarray.
Return Value:
Returns a newly allocated string representing the sequence of characters contained in the subarray of the character array argument.
Parameter Description data the character array offset the initial offset into the value of the String count the length of the value of the String
public static String valueOf(double d)Creates the string representation of the double argument.
The representation is exactly the one returned by the Double-.toString method of one argument .
Return Value:
Returns a newly allocated string containing a string representation of the double argument.
Parameter Description d a double
public static String valueOf(float f)Creates the string representation of the float argument.
The representation is exactly the one returned by the Float.toString method of one argument .
Return Value:
Returns a newly allocated string containing a string representation of the float argument.
Parameter Description f a float
public static String valueOf(int i)Creates the string representation of the int argument.
The representation is exactly the one returned by the Integer.toString method of one argument .
Return Value:
Returns a newly allocated string containing a string representation of the int argument.
Parameter Description i an int
public static String valueOf(long l)Creates the string representation of a the long argument.
The representation is exactly the one returned by the Long.toString method of one argument .
Return Value:
Returns a newly allocated string containing a string representation of the long argument.
Parameter Description l a long
public static String valueOf(Object obj)Creates the string representation of the Object argument.
Return Value:
Returns If the argument is null, then a string equal to "null"; otherwise the value of obj.toString() is returned.
Parameter Description obj an Object. See Also: toString in class Object .
© 1996 Sun Microsystems, Inc. All rights reserved.