Check out example codes for "java string contains char". It will help you in understanding the concepts better.

Code Example 1

/*
    This method returns true if the given string contains
    the char n. It is necessary due to the
    obsolescence of some compilers, which requires us
    to write our own contains method.
    */
    public static boolean contains_char (String main, char secondary)
    {
        boolean contains_result = false;
        for (int i = 0 ; i < input.length () ; i++)
        {
            if (input.charAt (i) == secondary)
            {
                contains_result = true;
                break;
            }
        }
        return contains_result;
    }

/*
for two chars:
*/
public static boolean contains_dualchar (String main, String secondary)
    {
        boolean contains_result = false;
        for (int i = 0 ; i < input.length () ; i++)
        {
            if (input.charAt (i) == secondary.charAt (0))
            {
                if (input.charAt (i + 1) == secondary.charAt (1))
                {
                    contains_result = true;
                    break;
                }
            }
        }
        return contains_result;
    }

Code Example 2

String s1 = "My name is GFG"; 
  
// prints true 
System.out.println(s1.contains("GFG")); 
  
// prints false 
System.out.println(s1.contains("geeks"));

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