futile.js

Stop rewriting the same utility functions for JavaScript! It's futile!

Welcome to fidian's utilities for ECMAScript. These are a few extremely useful functions that native JavaScript seems to lack, yet are found over and over in various projects. Instead of rewriting them every time, why not just include a library that has it all for you?

Function List

each(thing, callback, [context=null])

Used for iteration across objects and arrays. Calls callback with the given context for each item it comes across. The callback should have a function signature like this:

function yourCallback(value, key) { ... }

• When thing is an Object, calls callback once for each property that isn't inherited from the prototype.
• When thing is an Array, calls callback once for each item in the array and does not iterate across additional properties.
• When thing is a number, string, boolean or null, calls callback once with thing as the value and undefined as the key.
• When thing is undefined, no calls are made to callback.

Example:

futile.each([ 1, 2, 3 ], function (value) {
    console.log(value);
});

isArray(thing)

Returns true when thing is an instance of Array.

Example:

if (futile.isArray(variable)) {
    console.log('Yes, this is an array');
}

isFunction(thing)

Returns true when thing is an instance of Function or when it is otherwise callable. This was adapted from is-callable.

Example:

if (futile.isFunction(null)) {
    console.log('null is not a function so this does not run');
}

isObject(thing)

Returns true when thing is an object. This excludes Arrays and null and really means "it's an object".

Example:

console.log(futile.isObject({}));  // true
console.log(futile.isObject(7));  // false
console.log(futile.isObject(null));  // false - DIFFERS FROM "typeof"
console.log(futile.isObject([]));  // false - DIFFERS FROM "typeof"

Including in Your Project

This is an npm package:

npm install --save futile

It's also able to be loaded directly into a browser, thanks to fid-umd. This example loads the minified version.

<script src="path/to/futile.min.js"></script>