Leftpad, as it has to be: simple, fast, flexible

leftpad.js

// Leftpad - P(value, length, character, rightpad) - https://gist.github.com/moqmar/9ef4f0755d0a17b61458f35b91447bc1
function P(v,l,c,r) { v = v.toString(); while (v.length < l) v = r ? v + (c||0) : (c||0) + v; return v; }

// Usage: P(value, length, character, rightpad)
// P(25, 3)            ➜ "025"
// P(1, 3, " ")        ➜ "  1"
// P(25, 4, ".", true) ➜ "25.."

// public domain / cc0