【Better Code】repeat

function repeat(target, n) {
    return (new Array(n + 1)).join(target)
}

function repeat(target, n) {
    return Array.prototype.join.call({length: n + 1}, target)
}

var repeat = (function() {
    var join = Array.prototype.join,
        obj = {}
    return function(target, n) {
        obj.length = n + 1
        return join.call(obj, target)
    }
})();

function repeat(target, n) {
    var s = target,
        total = []
    while (n > 0) {
        if (n % 2 == 1) total[total.length] = s
        if (n == 1) break
        s += s
        n = n >> 1
    }

    return total.join(‘‘)
}

function repeat(target, n) {
    var s = target,
        c = s.length * n
    do {
        s += s
    } while (n = n >> 1)
    s = s.substring(0, c)
    return s
}

function repeat(target, n) {
    var s = target
        total = ‘‘
    while (n > 0) {
        if (n % 2 == 1) total += s
        if (n == 1) break
        s += s
        n = n >> 1
    }
    return total
}

function repeat(target, n) {
    if (n == 1) {
        return target
    }
    var s = repeat(target, Math.floor(n / 2))
    s += s
    if (n % 2) {
        s += target
    }
    return s
}