Javascript style wizard (final)

Proceed to the first two articles in sequence. This article serves as the final article. Blocks • has {} code, which can be processed by line breaks.

// badif (test)  return false;// goodif (test) return false;// goodif (test) {  return false;}// badfunction() { return false; }// goodfunction() {  return false;}

 

Comments • Use/**... */for multi-line comments /**...*/. Contains the description, parameter type, and return value.

// bad// make() returns a new element// based on the passed in tag name//// @param <String> tag// @return <Element> elementfunction make(tag) {  // ...stuff...  return element;}// good/** * make() returns a new element * based on the passed in tag name * * @param <String> tag * @return <Element> element */function make(tag) {  // ...stuff...  return element;}

 

• Use // For Single Row comments //. A single line comment is placed on a new line separately. Place a blank line before the comment.

// badvar active = true;  // is current tab// good// is current tabvar active = true;// badfunction getType() {  console.log('fetching type...');  // set the default type to 'no type'  var type = this._type || 'no type';  return type;}// goodfunction getType() {  console.log('fetching type...');  // set the default type to 'no type'  var type = this._type || 'no type';  return type;}

 

• Add fixme or todo before commenting on some issues, which will help developers quickly understand the code intent.

• Use // fixme: annotate the problem

function Calculator() {  // FIXME: shouldn't use a global here  total = 0;  return this;}

• Use // todo: comment out the solution to the problem

function Calculator() {  // TODO: total should be configurable by an options param  this.total = 0;  return this;}

 

Type Casting & coercion • Execute forced type conversion before declaration. • String

//  => this.reviewScore = 9;// badvar totalScore = this.reviewScore + '';// goodvar totalScore = '' + this.reviewScore;// badvar totalScore = '' + this.reviewScore + ' total score';// goodvar totalScore = this.reviewScore + ' total score';

• For numeric conversion, use parseint with the base number of type conversion.

• If parseint becomes your bottleneck and is in performance, you need to use the "shift" operation. Then, write down a comment to explain why you did this.

VaR inputvalue = '4'; // badvar val = new number (inputvalue); // badvar val = + inputvalue; // badvar val = inputvalue> 0; // badvar val = parseint (inputvalue); // goodvar val = Number (inputvalue); // goodvar val = parseint (inputvalue, 10 ); // good/*** parseint slows down my code. * To increase the speed, use the displacement operation to forcibly convert a string to a number. */Var val = inputvalue> 0;

• Boolean

var age = 0;// badvar hasAge = new Boolean(age);// goodvar hasAge = Boolean(age);// goodvar hasAge = !!age;

 

Constructors • extends objects using methods instead of using a new object.

function Jedi() {  console.log('new jedi');}// badJedi.prototype = {  fight: function fight() {    console.log('fighting');  },  block: function block() {    console.log('blocking');  }};// goodJedi.prototype.fight = function fight() {  console.log('fighting');};Jedi.prototype.block = function block() {  console.log('blocking');};

 

• Let the object method return this, which facilitates the Chain Lock operation of the method.

// badJedi.prototype.jump = function() {  this.jumping = true;  return true;};Jedi.prototype.setHeight = function(height) {  this.height = height;};var luke = new Jedi();luke.jump(); // => trueluke.setHeight(20) // => undefined// goodJedi.prototype.jump = function() {  this.jumping = true;  return this;};Jedi.prototype.setHeight = function(height) {  this.height = height;  return this;};var luke = new Jedi();luke.jump()  .setHeight(20);

• We can customize a tostring () method. -- Make sure it runs normally without any other impact.

function Jedi(options) {  options || (options = {});  this.name = options.name || 'no name';}Jedi.prototype.getName = function getName() {  return this.name;};Jedi.prototype.toString = function toString() {  return 'Jedi - ' + this.getName();};

 

 

The conclusion is finally completed, hoping to help everyone. Recommendation