module.exports = leftpad; function leftpad (str, len, ch) { str = String(str); var i = -1; if (!ch && ch !== 0) ch = ' '; len = len - str

module.exports = leftpad; function leftpad (str, len, ch) { str = String(str); var i = -1; if (!ch && ch !== 0) ch = ' '; len = len - str.length; while (++i < len) { str = ch + str; } return str; } Isn't that the least efficient way to do that function? Prepending a string has always been very expensive operation. Calculating needed length. Using repeat and just concatenating 2 strings would be faster.