JAVASCRIPT

replace array element javascript stack overflow

var index = items.indexOf(3452);

if (index !== -1) {
    items[index] = 1010;
}

replace array element javascript stack overflow

var index = items.indexOf(3452);

if (~index) {
    items[index] = 1010;
}

replace array element javascript stack overflow

if (haystack.includes(needle)) {
    // do your thing
}