It always a good practice to pass radix with parseInt – parseInt(string, radix) For decimal – parseInt(id.substring(id.length – 1), 10) If the radix parameter is omitted, JavaScript assumes the following: If the string begins with “0x”, the radix is 16 (hexadecimal) If the string begins with “0”, the radix is 8 (octal). This feature is … Read more
Array(5) gives you an array with length 5 but no values, hence you can’t iterate over it. Array.apply(null, Array(5)).map(function () {}) gives you an array with length 5 and undefined as values, now it can be iterated over. Array.apply(null, Array(5)).map(function (x, i) { return i; }) gives you an array with length 5 and values … Read more
Include ‘use strict’; as the first statement in a wrapping function, so it only affects that function. This prevents problems when concatenating scripts that aren’t strict. See Douglas Crockford’s latest blog post Strict Mode Is Coming To Town. Example from that post: (function () { ‘use strict’; // this function is strict… }()); (function () … Read more