bind() example

bind_ex.js

function sum () {
  var s = 0;
  for (var i = 0, len = arguments. length; i < len; i++) {
    s += arguments[i];
  }      
  return s;
}

// execute function and
// return 6, context is window
var simpleSum = sum(1, 2, 3) 

// preset first argument, 'this' will be null
// don't execute function yet!
var addToOne = sum.bind(null, 1);

// return 8 - 1 will be the first argument
addToOne(3, 4);

// preset two first arguments, 'this' will be null
var addToThree = sum.bind(null, 1, 2);

// return 10
addToThree(3, 4);