Array indexOf

HTML

<div id="results">
    sdsfsf
</div>

JavaScript

var results = document.getElementById("results");
var addResult = function(text) {
    var result = document.createElement("div");
    result.innerHTML = text;
    results.insertBefore(result);
};

var vehicles = ["car", "boat", "atv", "truck", "plane"];

var index = vehicles.indexOf("plane");
addResult("index of plane: " + index);

var numbers = [1,2,3,4,5,6,7,8,9];

index = numbers.indexOf("6");
addResult("index of 6: " + index);

index = numbers.indexOf(6);
addResult("index of 6: " + index);

var objects = [{ name: 'jim'}, { name: 'alex' }, { name: 'elijah' }];

index = objects.indexOf({ name: 'alex' });
addResult("index of alex: " +  index);

index = objects.indexOf(objects[1]);
addResult("index of alex: " +  index);