String Handling in Java

String Handling in Java

String is probably the most commonly used class in Java's class library.

String Handling in Java
String Handling in Java

  • The obvious reason for this is that strings are a very important part of programming.
  • The first thing to understand about strings is that every string you create is actually an object of type String. Even string constants are actually String objects.
  • For example, in the statement
  • System.out.println("This is a String, too");
  • the string "This is a String, too" is a String constant
  • Java defines one operator for String objects: +.
  • It is used to concatenate two strings. For example, this statement
  • String myString = "I" + " like " + "Java.";

results in myString containing "I like Java."
  1. char charAt(int index) : Returns the character at the specified index
  2. int compareTo(Object o) : Compares this String to another Object.
  3. int compareTo(String anotherString ) : Compares two string s lexicographically.
  4. int compareToIgnoreCase(String str) :Compares two string s lexicographically, ignoring case differences.
  5. String concat(String str) :Concatenates the specified string to the end of this string
  6. boolean contentEquals(StringBuffer sb) : Returns true if and only if this String represents the same sequence of characters as the specified StringBuffer.
  7. static String copyValueOf(char[] data) :Returns a String that represents the character sequence in the array specified.
  8. static String copyValueOf(char[] data, int offset, int count):Returns a String that represents the character sequence in the array specified.
  9. boolean endsWith(String suffix) :Tests if this string ends with the specified suffix.

  1. boolean equals(Object anObject):Compares this string to the specified object.
  2. boolean equalsIgnoreCase(String anotherString ):Compares this String to another String , ignoring case considerations.
  3. byte g etBytes() :Encodes this String into a sequence of bytes using the platform's default charset, storing the result into a new byte array.
  4. byte[] g etBytes(String charsetName) :Encodes this String into a sequence of bytes using the named charset, storing the result into a new byte array.
  5. void getChars(int srcBeg in, int srcEnd, char[] dst, int dstBeg in):Copies characters from this string into the destination character array.

  1. int hashCode() :Returns a hash code for this string .
  2. int indexOf(int ch) : Returns the index within this string of the first occurrence of the specified character.
  3. 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.
  4. int indexOf(String str): Returns the index within this string of the first occurrence of the specified substring .
  5. 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.
  6. String intern() :Returns a canonical representation for the string object.
  7. int lastIndexOf(int ch) :Returns the index within this string of the last occurrence of the specified character.

  1. int lastIndexOf(int ch, intfromIndex) : Returns the index within this string of the last occurrence of the specified character, searching backward starting at the specified index.
  2.  int lastIndexOf(String str): Returns the index within this string of the rightmost occurrence of the specified substring .
  3.  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.
  4.  int length() :Returns the length of this string .
  5.  boolean matches(String regex):Tells whether or not this string matches the g iven regular expression.
  6.  booleanregionMatches(boolean ignoreCase, int offset, String other, int ooffset, int len) : Tests if two string regions are equal.


  1. boolean reg ionMatches(int toffset, String other, int ooffset, int len) : Tests if two string regions are equal.
  2. String replace(char oldChar, char newChar): Returns a new string resulting from replacing all occurrences of oldChar in this string with newChar.
  3. String replaceAll(String reg ex, String replacement) : Replaces each substring of this string that matches the given regular expression with the given replacement.
  4.  String replaceFirst(String reg ex, String replacement) : Replaces the first substring of this string that matches the given regular expression with the given replacement.
  5.  String [] split(String reg ex) : Splits this string around matches of the given regular expression.
  6. String [] split(String reg ex, int limit) : Splits this string around matches of the
  7. given regular expression.
  8.  boolean startsWith(String prefix) : Tests if this string starts with the specified prefix.


  • booleanstartsWith(String prefix, inttoffset): Tests if this string starts with the specified prefix beg inning a specified index.
  • CharSequencesubSequence(intbeg inIndex, intendIndex) :Returns a new character sequence that is a subsequence of this sequence.
  • String substring (intbeg inIndex):Returns a new string that is a substring of this string .
  • String substring (intbeg inIndex, intendIndex): Returns a new string that is a substring of this string .
  • char[] toCharArray() :Converts this string to a new character array.
  • String toLowerCase(): Converts all of the characters in this String to lower case using the rules of the default locale.
  • String toLowerCase(Locale locale) :Converts all of the characters in this String to lower case using the rules of the g ivenLocale.

  • String toString() :This object (which is already a string !) is itself returned.
  • String toUpperCase() :Converts all of the characters in this String to upper case using the rules of the default locale.
  • String toUpperCase(Locale locale) : Converts all of the characters in this String to upper case using the rules of the given Locale.
  • String trim() :Returns a copy of the string , with leading and trailing whitespace omitted.
  • static String valueOf(primitive data type x) :Returns the string representation of the passed data type argument.