The bind method bind the object to the called function.
Creates a new function which, when called, has its this set to the provided value, with a given sequence of arguments preceding any provided when the new function was called.
In non-strict mode, the this of class methods or function is bound by default to their outer scope. In strict mode, the this of class methods or function is bound by default to the inner scope.
var x = "globalValue";
var fn = function () {
return this.x;
};
var fnBound = fn.bind( {x: "bindValue"} );
console.log( 'fn: ' + fn() ); // GlobalValue
console.log( 'fnBound: ' + fnBound() ); // bindValue
Bind and Call
var boundFn = function () {
return this.x;
}.bind( {x: 10} );
console.log ( 'boundFn: ' + boundFn() ); // 10
console.log ( 'boundFn + call x=20, still 10 : ' + boundFn.call( {x: 20} ) ); // still 10