Java String contains() method

contains() method returns true only if it contains the given sequence of characters otherwise it returns false.

syntax:

public boolean contains(CharSequence sequence)

parameters:

sequence : It is the sequence to be searched.

Returns:

It returns true when specified sequence character is found, Otherwise it returns false

Throws:

NullPointerException :when the sequence of characters is not found.

Example 1:

   public class ContainsEx1
{ 
public static void main(String args[])
{ 
  String name="tutorial and example"; 
  System.out.println(name.contains("tutorial")); 
  System.out.println(name.contains("and  "));
  System.out.println(name.contains("and"));
  System.out.println(name.contains("guide"));
  System.out.println(name.contains("example"));
  System.out.println(name.contains(" "));
     }
}

Output:

true                
false                
true              
false                
true               
true

Example 2: Case Sensitive

public class ContainsEx2
{ 
    public static void main(String[] args)
{ 
        String str = "Tutorial And Example World"; 
        boolean isContains = str.contains("World"); 
        System.out.println(isContains);
        if(str.contains("And1")){
            System.out.println("Welcome to the Java Tutorial and Example");    
          }else{
              System.out.println("J -->"+str.contains("And1"));
          } 
         System.out.println(str.contains("Tutorial And Example")); 
        // Case Sensitive 
        System.out.println(str.contains("Tutorial and Example")); // false 
    } 
}

Output:

true
J-->false
true
false

Example 3: Case Insensitive

public class ContainsEx3 {
    public static void main(String[] args) {
        String str = "tutorialandexample world";
        String str1 = "TUToRIalaNdExAmPLe WOrLd";
        System.out.println("Case Check: " +   str.contains(str1.toLowerCase()));
    }
}

Output:

 Case Check: true