Question

How do I write a java code that mimics charAt without using java API just primitives and no charAt to be used? I know it comes from primitives but I am confused on how to assemble the loops to derive my own charAt code

Answer 1

public class StringCharAt {

    public static char charAtIndex(String s, int index) {
        if (index < 0 || index >= s.length()) {
            throw new IllegalArgumentException("Index is invalid");
        }
        return s.toCharArray()[index];
    }

    public static void main(String[] args) {
        System.out.println(charAtIndex("hello", 0));
        System.out.println(charAtIndex("hello", 1));
        System.out.println(charAtIndex("hello", 2));
        System.out.println(charAtIndex("hello", 3));
        System.out.println(charAtIndex("hello", 4));
    }
}