SO - 20087022

by Arun P Johny

JavaScript

var obj = {
    a: 1,
    b: 2,
    c: 3,
    d: 4
};
var key;
for (var x in obj) {
    if (obj.hasOwnProperty(x) && obj[x] == 3) {
        key = x;
        break;
    }
}
console.log(key)