UnderScore Function Tutorial

/**
 * @author Piyush Arya
 * Module :- UnderScore.js Tutorial
 * Date Created :- Jan 2014
 */
var contactList = {
"returnList" : [{
"name" : "NAME",
"password" : "dummy",
"time" : "today",
"email" : "a.com"

}],

};

window.logger = function(param) {
return console.log(param);

};

var arr = ["1", "2", "3", "4", "5"], every = [true, 0, "hello"], invokeSort = [[3, 6, 5, 2, 4, 1],
 ["b", "d", "c", "a"]], invokeupper = ["b", "d", "c", "a"], arrColl = [1, 2, 3, 4, 5],
json = [{

"name" : "piyush",
"email" : "demo@gmail.com",
"age" : 25
}, {
"name" : "piyush",
"email" : "demo@yahoo.com",
"age" : 26
}, {
"name" : "arya",
"email" : "demo@hotmail.com",
"age" : 27
}];

/* ****  UNCOMMENT LOGGER TO SEE THE RESULT IN CONSOLE*****  */

/* ******************FUNCTIONS EXAMPLES *************************  */

/* ---------------------------bind Function Starts----------------------------------------- */

var o = {
greets : "Welcome"
}, f = function(name) {
return this.greets + " " + name;
};

var call = _.bind(f, o);

//logger(call("People"));
//The bind functions basically lets you keep the value of this whenever and wherever the function is called.
//This is specially useful when you’re working with event handlers where this is hijacked.

/* -----------------------bind Function end---------------------------------------------------- */


/* ------------------------bindAll Function Starts---------------------------------------------- */

var buttonView = {
label : 'Action Performed',
onClick : function() {
console.log('clicked: ' + this.label);
},
onmouseover : function() {
console.log('hovering: ' + this.label);
}
};
_.bindAll(buttonView, 'onClick', 'onmouseover');
// Bind methods
jQuery('.contact').bind('mouseout', buttonView.onmouseover);
// You can use n no functions into it.

/* --------------------------bindAll Function end------------------------------------------------ */

/* ---------------------------partial Function Starts-------------------------------------------- */

var add = function(a, b) {
return a * b;
};
add5 = _.partial(add, 5);
//logger(add5(10));
//_.partial(function, [*arguments])
// first parameter in _.partial will be the function and second parameter value.
// Once first value is passed with function it will be constant

/* --------------------------partial Function end------------------------------------------------ */


/* --------------------------delay Function Starts---------------------------------------------- */

var binding = _.bind(console.log);
//_.delay(binding, 1000, 'Delay');
// _.delay(function, wait, [*arguments])
// Will delay the function

/* --------------------------delay Function end----------------------------------------------- */


/* --------------------------defer Function Starts--------------------------------------------- */

_.defer(function() {
// console.log("This will execute when idle.");
});
/*The special utility function defer executes a function in a non-blocking */
/*fashion for the UI thread, waiting for the call stack to clear. */

/* --------------------------defer Function end---------------------------------------------------- */


/* --------------------------once Function Starts---------------------------------------------------- */

//var initializeOnce = _.once(createApplication);
//initializeOnce();
//initializeOnce();
// Application is only created once.


/* --------------------------once Function end---------------------------------------------------- */

/* --------------------------after Function Start---------------------------------------------------- */

//_.after(count, function)
//var renderNotes = _.after(notes.length, render);
//_.each(notes, function(note) {
//  note.asyncSave({success: renderNotes});
//});
// renderNotes is run once, after all notes have saved.

/* --------------------------------------after Function end---------------------------------------- */

/* --------------------------------------wrap Function Start--------------------------------------- */

var wraps = function(name) {
return "hello: " + name;
};
wraps = _.wrap(wraps, function(func) {
return "before, " + func("People") + ", after";
});
//logger(wraps());

// called function inside a function. Wrappped

/* --------------------------------------wrap Function end------------------------------------ */

/* --------------------------------------compose Function Start--------------------------------- */

var greeting = function(name) {
return "Welcome: " + name;
};
var override = function(statement) {
return statement.toUpperCase() + "!";
};
var welcome = _.compose(greeting, override);
//logger(welcome('People'));
/*each function consumes the return value of the function that follows. In math terms,
 composing the functions f(), g(), and h() produces f(g(h())).*/

/* ------------------------------compose Function end----------------------------- */

Click Here For Underscore Collections Functions with Examples

Click Here For Underscore Array Functions with Examples