Coding Guidelines / Coding Styles

conditions.js

// Wrong:
if (condition) alert(foo);

// Correct:
if (condition) {
	alert(foo);
}


//-------------------------------------------------


// Wrong:
var foo = NULL;

// Correct:
var foo = null;


//-------------------------------------------------


// Wrong:
if (condition == null) {
	
}

// Correct:
if (null === condition) {
	
}


//-------------------------------------------------


// Wrong: (if you compare with true, false, null or undefined)
if (condition === true) {
	
}

// Correct:
if (true === condition) {
	
}

//-------------------------------------------------

// Wrong:
if (condition) { alert(foo); }

// Correct:
if (condition) {
	alert(foo);
}

//-------------------------------------------------

// Wrong:
if(brochure.merchant.isActive() && brochure.getActiveDate() > dateFrom && brochure.getActiveDate() < dateTo && forceShowAll) {
}

// Wrong:
if(brochure.merchant.isActive() 
	&& brochure.getActiveDate() > dateFrom 
	&& brochure.getActiveDate() < dateTo 
	&& forceShowAll) {
}

// Correct:
var isMerchantActive = brochure.merchant.isActive();
var isWithinDateRange = brochure.getActiveDate() > dateFrom && brochure.getActiveDate() < dateTo;

if (isMerchantActive && isWithinDateRange && forceShowAll) {
}

function-declaration.js

// Wrong:
function GA(config) {
}

// Correct:
var GA = function(config) {
	
}; // <-- do not forget the semicolon or tiny kittens and a giraffe have to die

intendation-and-chaining.js

var foo = "This is a Hello World string";

// Wrong:
var element = foo.trim()
	.split(' ')
	.pop();
	
// Correct:
var fooElements = foo.trim().split(' ');
var element = fooElements.pop();

// also correct:
var foo = foo.trim();
var fooElements = foo.split(' ');
var element = fooElements.pop();

// also correct (if amount of chained functions is not too much. Decide on your own when to split it up)
var element = foo.trim().split(' ').pop();

scope.js

// Wrong:
var foo = function() {
	var me = this;
	var bar = function() {
		me.doThat();
	};
};


// Correct:
var foo = function() {
	var that = this; // If you have to save to use the scope in another scope use the name 'that' for it.
	var bar = function() {
		that.doThat();
	};
};

semicolons.js

// Wrong:
var foo = "bar"

// Correct:
var foo = "bar";

variable-declaration.js

// Wrong:
var foo = "foo",
	bar = "bar",
	hello = [true, false];
	
// Wrong:
var foo = "foo"
	, bar = "bar"
	, hello = [true, false];

// Correct:
var foo = "foo";
var bar = "bar";
var hello = [true, false];


//-------------------------------------------------


// Wrong:
var elements = new Array('foo', 'bar');

// Correct:
var elements = ['foo', 'bar'];


//-------------------------------------------------

// Wrong:
var map = {};
map.foo = "foo";
map.bar = "bar";

// Wrong:
var map = {
	foo: "foo"
	, bar: "bar"
	, baz: "baz"
};

// Correct:
var map = {
	foo: "foo",
	bar: "bar"
}; // <-- do not forget the semicolon or tiny little kittens have to die


//-------------------------------------------------


// Wrong:
var Long_Variablename;
var long_variable_name;
var longvariablename;

// Correct:
var longVariableName;


//-------------------------------------------------

// Wrong:
var myClass = function() {
	
};

// Correct: 
var MyClass = function() {
	
};


//-------------------------------------------------

// Wrong:
var myConstant = 10;
// Correct: (If you want to express that a variable is a constant use this syntax)
var MY_CONSTANT = 10;

variable-naming.js

// Wrong:
var text = true;
// Correct:
var hasText = true;

// Wrong:
var option = false;
// Correct:
var hasOption = false;

// Wrong:
var merchant = true;
// Correct:
var isMerchant = true;


//-------------------------------------------------


// Wrong:
var isNotProcessed = true;
// Wrong:
var notProcessed = true;
// Correct:
var isProcessed = false;


//-------------------------------------------------

// Use expressive names for all variables

// Wrong:
var err = new Error("Some error text");
// Correct:
var error = new Error("Some error text");

// Wrong:
var handler = function(req, res) {
};
// Correct:
var requestHandler = function(request, response) {
};