Click here to watch in Youtube :
https://www.youtube.com/watch?v=opWttGwhLoE&list=UUhwKlOVR041tngjerWxVccw

 Click the below Image to Enlarge

Java Tutorial : Java String (contains(CharSequence s) method)

ContainsDemo.java

/*
 * public boolean contains(CharSequence s)
 * 
 * Parameters: 
 * ----------  
 * s - the sequence to search for.
 * 
 * Returns: 
 * ------- 
 * Returns true if and only if this string contains
 * the specified sequence of char values.
 */

public class ContainsDemo
{

    public static void main(String[] args)
    {
        String str = "How are you peter?";

        boolean isExist = str.contains("are");
        System.out.println("contains(\"are\") =  " + isExist);

        /*
         * CharSequence is an interface that is implemented
         * by the String class. Therefore, you can use a
         * string as an argument for the contains() method.
         */

        isExist = str.contains("do");
        System.out.println("contains(\"do\")  =  " + isExist);

    }
}