js coding standards

js_coding_standards

Indentation - 2 spaces (tabs converted to spaces)

Line length - 80

comments up-to-date

block comments for documentation; typical - line comments
var variable; (each variable in a new declaration)

// named functions - mind the spaces; alignment of curly braces
function name() {
} 

// anonymous functions - mind the spaces; alignment
function () {
} 

// function invoked immediately, returning value
var a = (function () { . . . }());

Naming private members with _ (AVOID)

variables, functions - names in (camelCase)

constructor fuctions - names in (PascalCase); used with new prefix

global variables - names in (UPPERCASE)

simple statement ending with semicolon

compound statements - left curly brace at the end of the line begins the statement; content indented

return statements - no parenthesis around the return value; return value expression starts in the same line 

// spaces check
if (condition) {
  statements
} else {
  statements
}

if (condition) {
  statements
} else if (condition) {
  statements
} else {
  statements
}

for (intialization; condition; update) {
  // for arrays of definite size
}

for (variable in object) {
  // for objects
}

for (variable in object) {
  if (object.hasOwnProperty(variable)) {
    statements
  } 
}

while (condition) {
  statements
}

do {
  statements
} while (condition);   // semicolon check


// each case is aligned with switch
switch (expression) {
case expression:
  statements
  break; // break, return, or throw
default:
  statements
}


try {
  statements
} catch (variable) {
  statements
}

try {
  statements
} catch (variable) {
  statements
} finally {
  statements
}

Avoid use of the continue statement.

var a = {}; //instead of new Object()

var b = []; //instead of new Array()

Use the === and !== operators

var total = subtotal + (+myInput.value);


Avoid eval.
eval has aliases. Do not use the Function constructor. Do not pass strings to setTimeout or setInterval.