Call, Apply, and Bind, JS

//  CALL, APPLY, AND BIND

var person = {
    firstname: 'Jason',
    lastname: 'DeGraaf',
    getFullName: function() {
        var fullname = this.firstname + ' ' + this.lastname;
        return fullname;
    }
}

// bind creates a copy of whatever function you're calling it on.

var logName = function(lang1, lang2) {
    console.log('Logged: ' + this.getFullName());
    console.log('Arguments: ' + lang1 + ' ' + lang2);
    console.log('---------------')
}.bind(person);

// var logPersonName = logName.bind(person);


// call actually calls the function.  bind only creates copy
logName('en ', 'es');  //logPersonName();
logName.call(person, 'en', 'es');

//appy wants an array!  not a list.  but that's the only difference between call and apply
logName.apply(person, ['en', 'es'])



var person2 = {
    firstname: 'Jane',
    lastname: 'Doe'
}

// FUNCTION BORROWING

// This crazy set up borrows the 'this' from person object above.
console.log(person.getFullName.apply(person2));

// FUNCTION CURRYING
function mutliply(a,b) {
    return a*b;
}
// this bind method permamently sets "a" to 2.
var multiplyByTwo = mutliply.bind(this, 2);
console.log(multiplyByTwo(4));
//Answer will be 8.  If .bind was (this, 2, 5) set both a permanent. Answer 10.

var multiplyByThree = mutliply.bind(this, 3);
console.log(multiplyByThree(4));