Javascript Interview Question String Reverse letters in String

Introduction

Write a code to reverse a String.

Do not use native helpers like Array.reverse or String.reverse. 

function reverse(str) {
    //your code 
}
console.log(reverse('abcdefgh'));
console.log(reverse('abcdefghi'));
console.log(reverse('a'));
console.log(reverse(''));





/**
 * @function {public static} reverse
 *
 * Reverses the given `String`.
 *
 * @param {String} str - the `String` to reverse.
 *
 * @return the reversed `String`.
 */
function reverse(str) {
    if (!str) {
        return '';
    }

    var i = 0;
    var end = 0;
    var tmp = '';
    var len = str.length;


    var ar = str.split('');

    for (i = 0; i < Math.floor(len/2); i++) {
        end = len - i - 1;
        tmp = ar[end];
        ar[end] = ar[i];
        ar[i] = tmp;
    }

    return ar.join('');
}

console.log(reverse('abcdefgh'));
console.log(reverse('abcdefghi'));
console.log(reverse('a'));
console.log(reverse(''));

/*
Output: ($ /usr/bin/node 006.js)
hgfedcba
ihgfedcba
a
<empty string>
*/



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