String – II

String Functions – String class from package java.lang have some methods which can manipulate string literals.

String1.concat(String1) – This function used for joining two strings together. This can be done by: String1=String1+ String2.

Example:

String Str=“Hello”;

Str=Str.concat(“ Java”);  // or Str=Str + “Java” //Output Hello Java

String.trim() - Removes white space from both ends of this string.

Example:

String Str=“   Hello    ”;

System.out.println(Str.trim()); // Output -"Hello"

String.indexOf(char/string) - Returns the index within the string of the first occurrence of the specified character, if search fail then it will return -1.

Example:

String Str= “I live in India. I love my country India”

int L=Str.indexOf(“India”);  // Output - > 10 [ First occurrence of ‘India’ ]

String.indexOf(char/string, int) - Returns the index within this string of the first occurrence of the specified character, starting from the specified index, if search fail then it will return -1.

Example:

String Str= “I live in India. I love my country India”

int L=Str.indexOf(“India”,12);  // Output - > 35 [ Occurrence of ‘India’ after 12^th Postion ]

String.lastIndexof(char/String) - Returns the index within the string of the last occurrence of the specified character, if search fail then it will return -1.

lastIndexOf(String Str, int StartIndex)

int lastIndexOf(String str, int StartIndex): Returns the last index position of specified string starting from start Index.

Example:

String Str="This is a demo of lastIndexOf";
System.out.println(lastIndexOf('i', 3)); // Return 2.

Example:

String Str= “I live in India. I love my country India”

int L=Str.lastIndexOf(“India”);  // Output - > 35 [ last occurrence of ‘India’ ]

String.firstIndexof(char/String) - Returns the index within the string of the first occurrence of the specified character, if search fail then it will return -1.

Example:

String Str= “I live in India. I love my country India”

int L=Str.indexOf(“India”);  // Output - > 10 [ First occurrence of ‘India’ ]

String.startswith(String) -Tests if this string starts with the specified prefix and return a Boolean value.

Example:

System.out.println(“Hello Friends”.startsWith(“A”);  // Return ‘false’

String.endsWith(String) - Tests if this string ends with the specified suffix and return a Boolean value.

Example:

System.out.println(“Hello Friends.”.startsWith(“.”);  // Return ‘true’

String.replace(char, char) or String.replace(String, String)  - Returns a new string resulting from replacing all occurrences of oldChar in this string with newChar or oldString with the newString.

Example:

String test=”You is too good”;

test=rest.replace(“is”,”are”); // New value of tes=”You are too good”

String.toLowerCase() / String.toUpperCase() - Converts the String to lowercase / Converts the String to upper case.

Example:

System.out.println(“Hello Friends”.toUpperCase();  // “HELLO FRIENDS”

System.out.println(“Hello Friends”.toLowerCase(); // “hello friends”