JQuery plugin to filter a collection by an attribute

For markup such as this.

<input id="a" class="d" placeholder="AAA">

<input id="b" class="d" rel="whatever 1">

<input class="c d" placeholder="1CCC">

<input class="c d" rel="whatever 2">

<input class="c d" placeholder="2CCC">

Use as follows.

console.log( $('#a').hasAttr('placeholder') ); // 1 element console.log( $('#b').hasAttr('placeholder') ); // empty collection console.log( $('.c').hasAttr('placeholder') ); // 2 elements in collection console.log( $('.d').hasAttr('placeholder') ); // 3 elements in collection console.log( $('.d').hasAttr('rel') ); // 2 elements in collection console.log( $('#missing').hasAttr('placeholder') ); // empty collection