Javascript：如何只获得几个数字和数量 [英] Javascript: how to get only couple numbers and count of them

问题描述

我有2个输入，其中有输入的数字。单击检查按钮后，它应显示存在多少个数字，以及哪些数字。例如我输入2和9，它必须显示有4对情侣（2,4,6,8）。



我是什么尝试过：

I have 2 Input, in which are inputed numbers. after click on Check button it should show me how many couple numbers exist and which are those. For example i input 2 and 9, it must show me "There are 4 couple numbers (2,4,6,8)".

What I have tried:

<input type="text" id="tiv1" placeholder="Number 1">
		<input type="text" id="tiv2" placeholder="Number 2">
		<button onclick="check()">Check</button>
		<h1 id="result"></h1>

function check(){
	var a = Number(document.getElementById("tiv1").value);
	var b = Number(document.getElementById("tiv2").value);
	var count = 0;
	for(var i = a; i <= b; i++){
		if(i % 2 == 0){
			count++;
			document.getElementById("result").innerHTML = "There are " + count + " couple numbers " + " ( " + i + ")";
		}
	}
}

但在这种情况下而不是有4个情侣号码（2,4,6,8），它显示有4个情侣号码（8）。

有什么问题？

But in this case instead of "There are 4 couple numbers(2,4,6,8)", it shows me "There are 4 couple numbers (8)".
What's the problem?

推荐答案

解决方案：

Solution:

function check() {
            var a = Number(document.getElementById("Text1").value);
            var b = Number(document.getElementById("Text2").value);
            var count = 0;var number = "";
            for (var i = a; i <= b; i++) {
                if (i % 2 == 0) {
                    count++;
                    number += i + ",";
                   }
               } 
               document.getElementById("result").innerHTML = "There are " + count + " couple numbers " + " ( " + number + ")";
            
        }

首先是什么是夫妻号码？我猜你在谈论偶数。



无论如何，如果你在循环上编写innerHTML，那么你将只获得最终结果。

First of all what is couple number? I am guessing you are talking about even number.

Anyway, If you write on innerHTML on a loop then you will get only the final result.

function check(){
	var a = Number(document.getElementById("tiv1").value);
	var b = Number(document.getElementById("tiv2").value);
	var count = 0;
        var evenNUmbers = new Array();
	for(var i = a; i <= b; i++){
		if(i % 2 == 0){
			count++;
			evenNUmbers.push(i);
		}
	}
        document.getElementById("result").innerHTML = "There are " + count + " couple numbers " + " ( " + evenNUmbers.join() + ")";
}

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