 <p>Arrays are only meant to store numeric indices, you can create members like <code>Nom</code> but these will in no way react like a normal numeric index.*</p> <p>Either use an object, or push objects into your array.</p> <pre><code>var personnes=[]; personnes.push({ "Nom" : "Julie", "Age" : 100 }); personnes[0].Nom // -&gt; Julie </code></pre> <p>or</p> <pre><code>var personnes={}; personnes["Julie"] = 100; // equal to: personnes.Julie = 100; </code></pre> <p>or</p> <pre><code>var personnes={}; personnes["Julie"] = {"age":100 /*,"more attributes":"here"*/} </code></pre> <p>However, the last two notations assume that the names are unique!</p> <p>*You can do the following:</p> <pre><code>var ar = []; ar.attr = 5; ar.attr; // -&gt; 5 ar.length; // -&gt; 0, since attr is not enumerable // also all other regular array operation won't affect attr </code></pre>