Function Examples

by Joshua McNeese

JavaScript

// declaration
function fn1() {
    console.log("Hello from", this.name);
}

// expression
var fn2 = function() {
    console.log("Hello from", this.name, arguments);
};

// constructor
var fn3 = new Function("arg1", "console.log('Hello from', this.name, arg1);");

var obj1 = {
    name: "object 1"
};

var obj2 = {
    name: "object 2"
};

// call fn1 from the context of obj1
fn1.call(obj1);

// call fn2 from the context of obj2 with specified arguments
fn2.call(obj2, 1, 2, 3);

// call fn2 from the context of obj2 with specified arg array
fn2.apply(obj2, [4, 5, 6]);

// create a new function from fn3, binding it to the context of obj1, with a specified argument
var fn4 = fn3.bind(obj1, 'foo');

fn4();