Array.prototype.forEach.call(document.getElementsByTagName("input"), function(input){ var letra = input.id[input.id.length - 1]; input.addEventListener("change", function(){ document.getElementById("salida" + letra).innerText = input.value; }); });
<div> Rango A: <label id = "salidaA">0</label> <input type = "range" id = "rangoA" min = 0 max = 10 value = 0 /> </div> <div> Rango B: <label id = "salidaB">0</label> <input type = "range" id = "rangoB" min = 0 max = 10 value = 0 /> </div>