-.js

Array.prototype.remByVal = function(val) {
    for (var i = 0; i < this.length; i++) {
        if (this[i] === val) {
            this.splice(i, 1);
            i--;
        }
    }
    return this;
};
//Call like
[1, 2, 3, 4, 3].remByVal(3);

Array.prototype.remByVal = (val) ->
  for index in [0..@length - 1] when @[index] is val
    @splice index, 1
    index--
  @