如何计算所有生成的数字？

Question

What i'm trying to do:

• Count all the numbers that is generated every 5 seconds.

Actual Results

• Generates only numbers but, doesn't count them.

Expected Results

• Counts all the numbers that is generated and shown next to the question.

 function generator() { number = Math.floor(Math.random() * 11); setTimeout(function() { setTimeout(function() { document.getElementById("demo").innerHTML = number; generator(); }, 5000); }) } function add() { var count = 0 var element = document.getElementById("demo").innerHTML; if (element.innerHTML) { count++ document.getElementById("demo1").textContent = count++; } } generator(); add();

 <p id="demo"></p> How many numbers was generated? <p id="demo1"></p>

Answer 1

You call add() only once. You probably want to call it from inside the generate() function. Additionally var count = 0 should be outside of the add() function so that its value gets persisted across calls.

Sidenotes:

• You increase count two times per add() call.

• The outer setTimeout inside generate() is useless.

• number is a leaking global, you should declare it with var

Answer 2

I recommend you to use setInterval for repeated calls, and the data attribute to store the current count.

Extract the calls of document.getElementById to avoid look-for elements per setInterval cycle.

 var demoElem = document.getElementById("demo"); var countElem = document.getElementById("demo1"); function generator() { var interId = setInterval(function() { var number = Math.floor(Math.random() * 11); demoElem.textContent = number; add(); }, 2000); } function add() { countElem.dataset.count = Number(countElem.dataset.count) + 1; countElem.textContent = countElem.dataset.count; } generator();

 <p id="demo"></p> How many numbers was generated? <p id="demo1" data-count='0'></p>