Simple augmenting function to "Function.prototype" to extract just the integer part of a number and removes spaces from the ends of a string. This example was taken from the book "Javascript: The Good Parts".

extract_integer_from_number.js

//Define method to add a method available to all functions.
Function.prototype.method = function(name, func){
  this.prototype[name] = func;
  return this;
};


Number.method('integer', function( ){
  return Math[this < 0 ? 'ceil' : 'floor'](this);
})

console.log(10.3.integer( )); //Show 10

removes_spaces_from_end_of_string.js

//Define method to add a method available to all functions.
Function.prototype.method = function(name, func){
  this.prototype[name] = func;
  return this;
};

String.method('trim', function( ){
  var regex = /^\s+|\s+$/g;
  
  return this.replace(regex, '');
});

var dirtyName = "   Augusto Pedraza     ";

console.log(dirtyName);
console.log(dirtyName.trim( ));