repeat

gistfile1.js

function repeat(obj, times) {
    var res = typeof obj == 'string' ? '' : [];
    times = Math.max(1, times);
    do {
        if (times & 0x1) res = res.concat(obj);
        obj = obj.concat(obj);
    } while ((times >>= 1));
    
    return res;         
}

//Example 
console.log(repeat('a', 10)); //aaaaaaaaaa
console.log(repeat([1, 2, 3], 3)); //[1, 2, 3, 1, 2, 3, 1, 2, 3] 

//Init array with 0  
console.log(repeat([0], 10)); //[0, 0, 0, 0, 0, 0, 0, 0, 0, 0]