var array = [1, 2, 3], valor = 1; for(i = 0; i < array.length; i++){ document.body.innerHTML += array[i] + "<br />"; if(valor==array[i]) alert("coinciden"); } var index = array.indexOf(valor); alert(index); if(index != -1) array.splice(index, 1); document.body.innerHTML = array.join("<br />");