Java.lang.String Class
Java String Class
The String class in the Java.lang package , i.e Java.lang.String represents character strings. This class is used to implement all string literals in Java applications, such as “xyz.” Strings are immutable; once formed, their values cannot be modified.
Class declaration
The declaration of java.lang.String class is:
public final class String extends Object implements Serializable, Comparable<String>, CharSequence
Fields
| S.N | Fields & Description |
|---|---|
| 1. | static Comparator<String> CASE_INSENSITIVE_ORDER A Comparator that orders String objects as by compareToIgnoreCase. |
Class Constructors
| S.N | Constructors & Description |
|---|---|
| 1. | String() Initializes a newly created String object so that it represents an empty character sequence. |
| 2. | String(byte[] bytes) Constructs a new String by decoding the specified array of bytes using the platform’s default charset. |
| 3. | String(byte[] bytes, Charset charset) Constructs a new String by decoding the specified array of bytes using the specified charset. |
| 4. | String(byte[] bytes, int offset, int length) Constructs a new String by decoding the specified subarray of bytes using the platform’s default charset. |
| 5. | String(byte[] bytes, int offset, int length, Charset charset) Constructs a new String by decoding the specified subarray of bytes using the specified charset. |
| 6. | String(byte[] bytes, int offset, int length, String charsetName) Constructs a new String by decoding the specified subarray of bytes using the specified charset. |
| 7. | String(byte[] bytes, String charsetName) Constructs a new String by decoding the specified array of bytes using the specified charset. |
| 8. | String(char[] value) Allocates a new String so that it represents the sequence of characters currently contained in the character array argument. |
| 9. | String(char[] value, int offset, int count) Allocates a new String that contains characters from a subarray of the character array argument. |
| 10. | String(int[] codePoints, int offset, int count) Allocates a new String that contains characters from a subarray of the Unicode code point array argument. |
| 11. | String(String original) Initializes a newly created String object so that it represents the same sequence of characters as the argument; in other words, the newly created string is a copy of the argument string. |
| 12. | String(StringBuffer buffer) Allocates a new string that contains the sequence of characters currently contained in the string buffer argument. |
| 13. | String(StringBuilder builder) Allocates a new string that contains the sequence of characters currently contained in the string builder argument. |
java.lang.String Methods
The java.lang.String class has a number of methods which are listed below:
Member Methods
| S.N | Methods & Description |
|---|---|
| 1. | char charAt(int index) Returns the char value at the specified index. |
| 2. | int codePointAt(int index) Returns the character (Unicode code point) at the specified index. |
| 3. | int codePointBefore(int index) Returns the character (Unicode code point) before the specified index. |
| 4. | int codePointCount(int beginIndex, int endIndex) Returns the number of Unicode code points in the specified text range of this String. |
| 5. | int compareTo(String anotherString) Compares two strings lexicographically. |
| 6. | int compareToIgnoreCase(String str) Compares two strings lexicographically, ignoring case differences. |
| 7. | String concat(String str) Concatenates the specified string to the end of this string. |
| 8. | boolean contains(CharSequence s) Returns true if and only if this string contains the specified sequence of char values. |
| 9. | boolean contentEquals(CharSequence cs) Compares this string to the specified CharSequence. |
| 10. | boolean contentEquals(StringBuffer sb) Compares this string to the specified StringBuffer. |
| 11. | static String copyValueOf(char[] data) Equivalent to valueOf(char[]). |
| 12. | static String copyValueOf(char[] data, int offset, int count) Equivalent to valueOf(char[], int, int). |
| 13. | boolean endsWith(String suffix) Tests if this string ends with the specified suffix. |
| 14. | boolean equals(Object anObject) Compares this string to the specified object. |
| 15. | boolean equalsIgnoreCase(String anotherString) Compares this String to another String, ignoring case considerations. |
| 16. | static String format(String format, Object… args) Returns a formatted string using the specified format string and arguments. |
| 17. | static String format(Locale l, String format, Object… args) Returns a formatted string using the specified locale, format string, and arguments. |
| 18. | byte[] getBytes() Encodes this String into a sequence of bytes using the platform’s default charset, storing the result into a new byte array. |
| 19. | byte[] getBytes(Charset charset) Encodes this String into a sequence of bytes using the given charset, storing the result into a new byte array. |
| 20. | byte[] getBytes(String charsetName) Encodes this String into a sequence of bytes using the named charset, storing the result into a new byte array. |
| 21. | void getChars(int srcBegin, int srcEnd, char[] dst, int dstBegin) Copies characters from this string into the destination character array. |
| 22. | int hashCode() Returns a hash code for this string. |
| 23. | int indexOf(int ch) Returns the index within this string of the first occurrence of the specified character. |
| 24. | int indexOf(int ch, int fromIndex) Returns the index within this string of the first occurrence of the specified character, starting the search at the specified index. |
| 25. | int indexOf(String str) Returns the index within this string of the first occurrence of the specified substring. |
| 26. | int indexOf(String str, int fromIndex) Returns the index within this string of the first occurrence of the specified substring, starting at the specified index. |
| 27. | String intern() Returns a canonical representation for the string object. |
| 28. | boolean isEmpty() Returns true if, and only if, length() is 0. |
| 29. | static String join(CharSequence delimiter, CharSequence… elements) Returns a new String composed of copies of the CharSequence elements joined together with a copy of the specified delimiter. |
| 30. | static String join(CharSequence delimiter, Iterable<? extends CharSequence> elements) Returns a new String composed of copies of the CharSequence elements joined together with a copy of the specified delimiter. |
| 31. | int lastIndexOf(int ch) Returns the index within this string of the last occurrence of the specified character. |
| 32. | int lastIndexOf(int ch, int fromIndex) Returns the index within this string of the last occurrence of the specified character, searching backward starting at the specified index. |
| 33. | int lastIndexOf(String str) Returns the index within this string of the last occurrence of the specified substring. |
| 34. | int lastIndexOf(String str, int fromIndex) Returns the index within this string of the last occurrence of the specified substring, searching backward starting at the specified index. |
| 35. | int length() Returns the length of this string. |
| 36. | boolean matches(String regex) Tells whether or not this string matches the given regular expression. |
| 37. | int offsetByCodePoints(int index, int codePointOffset) Returns the index within this String that is offset from the given index by codePointOffset code points. |
| 38. | boolean regionMatches(int toffset, String other, int ooffset, int len) Tests if two string regions are equal. |
| 39. | boolean regionMatches(boolean ignoreCase, int toffset, String other, int ooffset, int len) Tests if two string regions are equal. |
| 40. | String replace(char oldChar, char newChar) Returns a string resulting from replacing all occurrences of oldChar in this string with newChar. |
| 41. | String replace(CharSequence target, CharSequence replacement) Replaces each substring of this string that matches the literal target sequence with the specified literal replacement sequence. |
| 42. | String replaceAll(String regex, String replacement) Replaces each substring of this string that matches the given regular expression with the given replacement. |
| 43. | String replaceFirst(String regex, String replacement) Replaces the first substring of this string that matches the given regular expression with the given replacement. |
| 44. | String[] split(String regex) Splits this string around matches of the given regular expression. |
| 45. | String[] split(String regex, int limit) Splits this string around matches of the given regular expression. |
| 46. | boolean startsWith(String prefix) Tests if this string starts with the specified prefix. |
| 47. | boolean startsWith(String prefix, int toffset) Tests if the substring of this string beginning at the specified index starts with the specified prefix. |
| 48. | CharSequence subSequence(int beginIndex, int endIndex) Returns a character sequence that is a subsequence of this sequence. |
| 49. | String substring(int beginIndex) Returns a string that is a substring of this string. |
| 50. | String substring(int beginIndex, int endIndex) Returns a string that is a substring of this string. |
| 51. | char[] toCharArray() Converts this string to a new character array. |
| 52. | String toLowerCase() Converts all of the characters in this String to lower case using the rules of the default locale. |
| 53. | String toLowerCase(Locale locale) Converts all of the characters in this String to lower case using the rules of the given Locale. |
| 54. | String toString() This object (which is already a string!) is itself returned. |
| 55. | String toUpperCase() Converts all of the characters in this String to upper case using the rules of the default locale. |
| 56. | String toUpperCase(Locale locale) Converts all of the characters in this String to upper case using the rules of the given Locale. |
| 57. | String trim() Returns a string whose value is this string, with any leading and trailing whitespace removed. |
| 58. | static String valueOf(boolean b) Returns the string representation of the boolean argument. |
| 59. | static String valueOf(char c) Returns the string representation of the char argument. |
| 60. | static String valueOf(char[] data) Returns the string representation of the char array argument. |
| 61. | static String valueOf(char[] data, int offset, int count) Returns the string representation of a specific subarray of the char array argument. |
| 62. | static String valueOf(double d) Returns the string representation of the double argument. |
| 63. | static String valueOf(float f) Returns the string representation of the float argument. |
| 64. | static String valueOf(int i) Returns the string representation of the int argument. |
| 65. | static String valueOf(long l) Returns the string representation of the long argument. |
| 66. | static String valueOf(Object obj) Returns the string representation of the Object argument. |
Methods inherited by Java.lang.String
This class inherits the methods of the following class:
- java.lang.Object
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