Underscore.js Arrays: indexOf
HTML
<script src="http://documentcloud.github.com/underscore/underscore-min.js"></script>
<a target="parent" href="http://underscorejs.org/#indexOf">Learn More</a>
JavaScript
var testIndexOf = _.indexOf([1, 2, 3, 5, 6, 7, 8], 5);
var data = [{id: "1", }]
console.log(testIndexOf);
//3, the index of 5