如何在每 30 秒后更改 Javascript 中的变量值

Question

i have an array like

  var A=["2","4","5"];

I have a set of value in one array. But i need show value only by one between 30 seconds. Can anyone help me.

Answer 1

get each value of items in callback after 30 seconds

 function getValue(items, cb, i) { i = i || 0; if (i < items.length) { setTimeout(function() { cb(items[i]) i++; getValue(items, cb, i); }, 30 * 1000); } } getValue(['1', 2, 3], function(val) { console.log(val); });

Answer 2

You are looking for the setInterval() method.

 (function() { var source = ["2", "4", "5"]; var delay = 1000; // use 30000 for 30 seconds var currentIndex = 0; var A = source[currentIndex]; // Starting value window.console.log(A); // demo var intervalId = setInterval(function() { currentIndex += 1; A = source[currentIndex]; window.console.log(A); // demo // Clear interval if (source.length === currentIndex + 1) { clearInterval(intervalId); } }, delay); })();