验证选择 JavaScript

Question

我需要一些帮助，我知道这是一个非常简单的解决方案，但我总是卡在代码的这一部分，我需要验证我对 1、2 或 3 的选择并访问该网站 提前致谢

对于某些人来说，我需要用户选择 1 2 或 3，用户选择 1 2 或 3 将提示他们输入高度和宽度 500，如果输入正确，则输出错误低于输出错误 转到该站点只需要它来验证选择

function redirect() {
  
  var choice=0;
	var height;
	var width;
	var url = Number (prompt("Pick a site? 1. xxxx 2. xxxx 3. xxx", ""));
   	switch (url)
	
				
	{				
	case 1:
			
			while(!isFinite(height) || height < 500) {
    		height = prompt("Enter a height > 500");	
			}
					
			while(!isFinite(width) || width < 500) {
    		width = prompt("Enter a width > 500");
			}
		window.open(url="http://www.xxx", "myWindow","status = 1, height = 500, width = 500, resizable = 0");			
		break;
			
	case 2:
			
			while(!isFinite(height) || height < 500) {
    		height = prompt("Enter a height > 500");
			}
					
			while(!isFinite(width) || width < 500) {
    		width = prompt("Enter a width > 500");
			}
		window.open(url="http://xxx", "myWindow","status = 1, height = 500, width = 500, resizable = 0");
		break;
				
	case 3:
			
			while(!isFinite(height) || height < 500) {
    		height = prompt("Enter a height > 500");
			}
					
			while(!isFinite(width) || width < 500) {
    		width = prompt("Enter a width > 500");
			}
		
		window.open(url="http://www.xxx", "myWindow","status = 1, height = 500, width = 500, resizable = 0");
		break;
		
		default:
		alert("Please enter number 1, 2, or 3 to select a website");	
		return false;		
		}// end switch
	
		return;
}

<button type="button" onclick="redirect()" onsubmit="return validateForm()">Go to other websites</button> 

Answer 1

你已经有一段时间循环了，所以我不知道你为什么不直接使用类似的逻辑来检查。

var url;
while (url === undefined || [1,2,3].indexOf(url) === -1)
{
  url = prompt("Pick a site? 1. xxxx 2. xxxx 3. xxx", "");
  if (url === null)
  {
    return false;
  }
  url = Number(url);
}

return url === null是允许用户在决定取消或W/E时实际退出无限提示循环。您也应该将其用于宽度/高度(尽管这取决于您(。

以下代码段：

function redirect() {
  
  var choice=0;
	var height;
	var width;
  var url;
	
  let i = 0;
  while (url === undefined || [1,2,3].indexOf(url) === -1)
  {
    url = prompt("Pick a site? 1. xxxx 2. xxxx 3. xxx", "");
    if (url === null)
    {
      return false;
    }
    url = Number(url);
  }
   	
  switch (url)			
	{				
	case 1:
			
			while(!isFinite(height) || height < 500) {
    		height = prompt("Enter a height > 500");	
			}
					
			while(!isFinite(width) || width < 500) {
    		width = prompt("Enter a width > 500");
			}
		window.open(url="http://www.xxx", "myWindow","status = 1, height = 500, width = 500, resizable = 0");			
		break;
			
	case 2:
			
			while(!isFinite(height) || height < 500) {
    		height = prompt("Enter a height > 500");
			}
					
			while(!isFinite(width) || width < 500) {
    		width = prompt("Enter a width > 500");
			}
		window.open(url="http://xxx", "myWindow","status = 1, height = 500, width = 500, resizable = 0");
		break;
				
	case 3:
			
			while(!isFinite(height) || height < 500) {
    		height = prompt("Enter a height > 500");
			}
					
			while(!isFinite(width) || width < 500) {
    		width = prompt("Enter a width > 500");
			}
		
		window.open(url="http://www.xxx", "myWindow","status = 1, height = 500, width = 500, resizable = 0");
		break;
		
		default:
		break;
		}// end switch
	
		return;
}

<button type="button" onclick="redirect()" onsubmit="return validateForm()">Go to other websites</button>