使用 for 循环比较数组中的数字答案

【问题标题】：Compare numbers in Array using for loop使用 for 循环比较数组中的数字
【发布时间】：2015-06-16 01:05:00
【问题描述】：

我有一个问题要解决，我必须使用循环遍历每个位置一组“中奖号码”，用于检查可变客户编号（从键盘输入）是否与任何中奖号码匹配。我必须使用 For 循环遍历中奖号码数组中的每个位置，并将客户号码与数组包含的每个号码进行比较。我不能使用任何方法来解决这个问题谢谢你的帮助！这是我到目前为止所做的：

var customerNumbers = prompt("Enter your number:");
var winningNumbers = [12, 17, 24, 37, 38, 43];    

for (var i = 0; i < winningNumbers.length; i++) {

    if (customerNumbers == 12 || //condition determinates the winning numbers
        customerNumbers == 17 ||
        customerNumbers == 24 ||
        customerNumbers == 37 ||
        customerNumbers == 38 ||
        customerNumbers == 43)
        alert("This week Winning numbers are:" + "\n" + "\n" + winningNumbers + "\n" + "\n" + "The customer's Number is:" + "\n" + "\n" + customerNumbers + "\n" + "\n" + "We have a match and a winner!");
} else {
    alert("This week Winning numbers are:" + "\n" + "\n" + winningNumbers + "\n" + "\n" + "The customer's Number is:" + "\n" + "\n" + customerNumbers + "\n" + "\n" + "Sorry you are not a winner this week");
}

【问题讨论】：

那么问题出在哪里？上面的代码不起作用？
你对 for 循环了解多少？你试过什么？您尝试过的解决方案有什么问题？
“我无法使用任何方法来解决这个问题”是什么意思？这是某种家庭作业，否则这是一种愚蠢的约束？

标签： javascript arrays loops

【解决方案1】：

你应该使用indexOf()来检查customerNumbers是否存在于winningNumbers中

indexOf() 方法返回可以在数组中找到给定元素的第一个索引，如果不存在，则返回 -1。

脚本

var customerNumbers=prompt("Enter your number:" );
var winningNumbers=[12, 17, 24, 37, 38, 43];
if (winningNumbers.indexOf(parseInt(customerNumbers, 10)) > -1) 
    alert("This week Winning numbers are:"+"\n"+"\n"+winningNumbers+"\n"+"\n"+"The customer's Number is:"+"\n"+"\n"+customerNumbers+"\n"+"\n"+"We have a match and a winner!");
} else {
    alert("This week Winning numbers are:"+"\n"+"\n"+winningNumbers+"\n"+"\n"+"The customer's Number is:"+"\n"+"\n"+customerNumbers+"\n"+"\n"+"Sorry you are not a winner this week");
}

【讨论】：

他说：不能用任何方法

【解决方案2】：

以下解决方案循环所有中奖号码并检查是否匹配

var customerNumbers = prompt("Enter your number:");
var winningNumbers = [12, 17, 24, 37, 38, 43];
var match = false;

for (var i = 0; i < winningNumbers.length && !match ; i++) {
  if (winningNumbers[i] == customerNumbers) {
    match = true;
  }
}

if (match)
  alert("This week Winning numbers are:" + "\n" + "\n" + winningNumbers + "\n" + "\n" + "The customer's Number is:" + "\n" + "\n" + customerNumbers + "\n" + "\n" + "We have a match and a winner!");
} else {
  alert("This week Winning numbers are:" + "\n" + "\n" + winningNumbers + "\n" + "\n" + "The customer's Number is:" + "\n" + "\n" + customerNumbers + "\n" + "\n" + "Sorry you are not a winner this week");
}

【讨论】：