exercises.md

Exercises

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Closures

Open exercises/make.html in a browser. The code will also be placed in this html file.

"make" library

Build a tag library that creates elements of the following types in the least LOC: a, div, span, form, h1, h2, h3, h4.

Example usage:

var h1 = make.h1();
h1.innerHTML = 'Hello World';
document.body.appendChild(h1);

var a = make.a();
a.href= 'http://canjs.com';
a.innerHTML = 'CanJS';
document.body.appendChild(a);

HINTS: Code is ‘built’ one statement at a time. document.createElement('h1') – creates and returns an 'h1' element.

Context

Implement this exercise in exercises/context_prototypes/index.js. You can test your code by opening exercises/context_prototypes/test.html in a browser.

DOT()

Write the dot operator as if it was implemented in JS.

var Person = function(name) {
	this.name = name;
}

Person.prototype.isPerson = true;

var person = new Person('Smith');
DOT(person, 'name');        //person.name
DOT(person, 'isPerson');    //person.isPerson

Hints:

DOT takes the object and the property DOT must walk up the proto chain object.hasOwnProperty('PROPERTY_NAME') returns if an object has a 'direct' property.

DOTCALL()

Write the dot [[call]] operator as if it was implemented in JS.

var Person = function(name) {
	this.name = name;
}

Person.prototype.speak = function(){ 
  console.log('Hello! ' + this.name);
}
var person = new Person('Smith');

DOTCALL( obj, propertyName, args );
DOTCALL( person, 'speak' , [] );  //person.speak()

Hints:

DOTCALL must retain context