[Chapter 25] 25.57 java.lang.String (JDK 1.0)

25.57 java.lang.String (JDK 1.0)

The String class represents a string of characters. A String object is created by the Java compiler whenever it encounters a string in doublequotes--this method of creation is usually simpler than using a constructor. A number of the methods of this class provide useful string manipulation functions. length() returns the number of characters in a string. charAt() extracts a character from a string. compareTo() compares two strings. equalsIgnoreCase() tests string for equality, ignoring case. startsWith() and endsWith() compare the start and end of a string to a specified value. indexOf() and lastIndexOf() search forward and backwards in a string for a specified character or substring. substring() returns a substring of a string. replace() creates a new copy of the string with one character replaced by another. toUpperCase() and toLowerCase() convert the case of a string. trim() strips whitespace from the start and end of a string. concat() concatenates two strings, which can also be done with the + operator.

Note that String objects are immutable--there is no setCharAt() method to change the contents. The methods above that return a String do not modify the string they are passed, but instead return a modified copy of the string. Use a StringBuffer if you want to manipulate the contents of a string, or use toCharArray() to convert a string to an array of char values.

The static valueOf() methods convert various Java primitive types to strings.


public final class String extends Object implements Serializable {

    // Public Constructors

            public String();

            public String(String value);

            public String(char[] value);

            public String(char[] value, int offset, int count);

        #   public String(byte[] ascii, int hibyte, int offset, int count);

        #   public String(byte[] ascii, int hibyte);

        1.1public String(byte[] bytes, int offset, int length, String enc) throws UnsupportedEncodingException;

        1.1public String(byte[] bytes, String enc) throws UnsupportedEncodingException;

        1.1public String(byte[] bytes, int offset, int length);

        1.1public String(byte[] bytes);

            public String(StringBuffer buffer);

    // Class Methods

            public static String copyValueOf(char[] data, int offset, int count);

            public static String copyValueOf(char[] data);

            public static String valueOf(Object obj);

            public static String valueOf(char[] data);

            public static String valueOf(char[] data, int offset, int count);

            public static String valueOf(boolean b);

            public static String valueOf(char c);

            public static String valueOf(int i);

            public static String valueOf(long l);

            public static String valueOf(float f);

            public static String valueOf(double d);

    // Public Instance Methods

            public char charAt(int index);

            public int compareTo(String anotherString);

            public String concat(String str);

            public boolean endsWith(String suffix);

            public boolean equals(Object anObject);  // Overrides Object

            public boolean equalsIgnoreCase(String anotherString);

        #   public void getBytes(int srcBegin, int srcEnd, byte[] dst, int dstBegin);

        1.1public byte[] getBytes(String enc) throws UnsupportedEncodingException;

        1.1public byte[] getBytes();

            public void getChars(int srcBegin, int srcEnd, char[] dst, int dstBegin);

            public int hashCode();  // Overrides Object

            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 native 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(int toffset, String other, int ooffset, int len);

            public boolean regionMatches(boolean ignoreCase, int toffset, String other, int ooffset, int len);

            public String replace(char oldChar, char newChar);

            public boolean startsWith(String prefix, int toffset);

            public boolean startsWith(String prefix);

            public String substring(int beginIndex);

            public String substring(int beginIndex, int endIndex);

            public char[] toCharArray();

        1.1public String toLowerCase(Locale locale);

            public String toLowerCase();

            public String toString();  // Overrides Object

        1.1public String toUpperCase(Locale locale);

            public String toUpperCase();

            public String trim();

}

25.57 java.lang.String (JDK 1.0)

Passed To:

Returned By:

Type Of:


java.lang.StackOverflowError (JDK 1.0)		java.lang.StringBuffer (JDK 1.0)