Question

我在html中有三个复选框在Javascript中，我有变量newspaper = "jang,News,Dawn";

现在我想检查基于报纸值的复选框，如果它只包含jang那么只有jang复选框应该检查是否包含jang，News，Dawn然后应该检查所有三个复选框。

我写的代码总是检查最后两个错误的复选框。

我的代码是：

var newspaper = document.forms[0].newspaper;
var a = "Jang,News";

var news = ["Jang", "Dawn", "News"]
for (i = 0; i < news.length; i++)
{
    if (a.indexOf(news[i]))
    {
        newspaper[i].checked = true;
    }
}

<input type="checkbox" name="newspaper[]"  value="Jang">Jang<br />
<input type="checkbox" name="newspaper[]"  value="Dawn">Dawn<br />
<input type="checkbox" name="newspaper[]"  value="News">The News

Answer 1

如果您只想使用Javascript进行此操作，则必须对代码进行一些更改：

将所有复选框的名称更改为“报纸”（不带方括号）

<input type="checkbox" name="newspaper"  value="Jang"/>Jang<br />
<input type="checkbox" name="newspaper"  value="Dawn"/>Dawn<br />
<input type="checkbox" name="newspaper"  value="News"/>The News

检查indexOf返回值不等于-1：

if (a.indexOf(news[i]) != -1) {
    newspaper[i].checked = true;
}

这是working demo。

Answer 2

var newspaper = document.forms[0]["newspaper[]"];
var a = "Jang,News";
for (i = 0; i < newspaper.length; i++)
{
       if(a.indexOf(newspaper[i].value) > -1){
             newspaper[i].checked = true;
          }
}

是的，我会检查您的代码以及元素的名称。但在这里，这很有效。

http://jsfiddle.net/3qeeox0a/

Answer 3

试试这个 -

var newspaper = document.forms[0].newspaper;
    var a = "Jang,News";

    var news = ["Jang","Dawn", "News"]
    for (i = 0; i < news.length; i++)
    {
        if (a.indexOf(news[i]) != 1)
        {
            newspaper[i].checked = true;
        }
    }

<强>小提琴： - http://jsfiddle.net/um0y5wrp/9/

Answer 4

请更改代码，并将其替换为：

   if (a.indexOf(news[i]))
            {newspaper[i].checked = true; 
   }

由：

for(j = 0; j < newspaper.length; j++){
   if(newspaper[j].value == newspaper[i].value){
      if (a.indexOf(news[i])){
         newspaper[j].checked = true;
      }
   }
}

如何检查javascript中的复选框

4 个答案: