if statement not evaluating but console log shows it should-CodePudding

I am trying to write a function to get the length of a string without using the .length property nor any loops or built in methods. I am using recursion, however, the stopping statement is not evaluating and causing a stack overflow. I tried console logging string[i] and sure enough, once the length is reached, it console logs "undefined" but the if statement still won't evaluate.

const getLength = (string, i = 0) => {
    if (string[i] === 'undefined') return 0;
    return 1   getLength(string, i 1);
}

console.log(getLength("what is going on??")); //18

CodePudding user response：

the if-state should be string[i] === undefined

CodePudding user response：

Your test for undefined is not working

You can test for falsy or more detailed

Here is just a falsy one, it will fail on falsy values like 0

const getLength = (string, i = 0) => string[i] ?  1   getLength(string, i 1) : 0;
console.log(getLength("what is going on??")); //18