Find length of String without using java inbuilt length method

There are two ways to find the length of string without using inbuilt length method:

1. Using toCharArray
2. Using StringIndexOutOfBoundsException

Using toCharArray:

• Conver string to char array using toChararray method
• Iterate over char array and incrementing length variable.

class LenghtOfStringMain{

        public static void main(String args[]){

                String str1="This is hello world";

                System.out.println("length is :"+getLengthOfStringWithCharArray(str1));

        }

        public static int getLengthOfStringWithCharArray(String str){

                int length=0;

                char[] strCharArray=str.toCharArray();

                for(char c:strCharArray){

                        length++;

                }

                return length;

        }

Output:

        length is: 19

Using StringIndexOutOfBoundsException:

• Initialize i with 0 and iterate over String without specifying any condition. So it will be always true.
• Once value of i will be more than length of String, it will throw StringIndexOutOfBoundsException exception.
• We will catch the exception and return i after coming out of catch block.

class LenghtOfStringMain

{

        public static void main(String args[])

        {

                String str1="This is hello world";

                System.out.println("length is :"+getLengthOfString(str1));

        }

        public static int getLengthOfString(String str)

        {

                int i=0;

                try{

                        for(i=0;;i++){

                        str.charAt(i);

                        }

                }

                catch(Exception e)

                {

                }

                return i;

        }

}

Output:

        length is:19