JS Bin// source https://jsbin.com/xejuloh

Memoize A Constant

function baz() {
    let val;
    return function bar() {
        if (val === undefined) {
            console.log('working');
            val = ['values', 'values']
            return val;
        } else {
            return val;
        }
    }
}


let foo = baz();
for (var i = 0; i < 10; i++) {
    console.log(foo());
}