Question

以下代码有什么问题（我认为它与if语句有关），我试过在线查找，但没有成功？

<form action="#" method="post" name="formSeven">
  <p><input type="text" name="z11" value="" size="4" /> <span> Adjusted BMI </span></p>
  <p><input type="text" name="z12" value="" size="4" /> <span> Age in years </span></p>
  <p><input type="text" name="z13" value="" size="4" /> <span> Male or Female </span></p>
  <p><input type="text" name="result7" value="" size="4" /> <span> BF% </span></p>
  <p><input onclick="calculate7()" type="BUTTON" value="Calculate" /></p>
</form>

<script type="text/javascript">// 
function calculate7() {
    var x = document.formSeven.z11.value;
    var y = document.formSeven.z12.value;
    var z = document.formSeven.z13.value;
    if (z == "Female"){
        document.formSeven.result7.value = x+y-5.4;
    }
    else if (z == "Male") {
        document.formSeven.result7.value = x+y-16.2;
    }
}
// ]]></script>

Answer 1

最好输入性别是做出选择，因为你不必担心用户的错误：

<select id="gender" >
<option value="0" selected="selected">Female</option>
<option value="1">Male</option>
</select>

然后在你的javascript中

(parseInt(document.getElementById('gender').value) === 0) ? document.formSeven.result7.value = x+y-5.4:document.formSeven.result7.value = x+y-16.2;

Answer 2

if (z == "Female")
 document.formSeven.result7.value = x+y-5.4;  
else if (z == "Male")
 document.formSeven.result7.value = x+y-16.2;

Answer 3

使用

if (z === "Female"){
document.formSeven.result7.value = x+y-5.4;
}

Answer 4

这是做你想做的事的最短路。它还为您提供了一些错误余量，因为它不区分大小写。

document.formSeven.result7.value=(z.toLowerCase()=='female'?(x+y-5.4):(x+y-16.2));

这里

document.formSeven.result7.value=(z.toLowerCase()=='female'?(x+y-5.4):(z.toLowerCase()=='male'?(x+y-16.2):''));

用你想要的任何值替换最新的z。

以下是您的完整代码：

<form action="#" method="post" name="formSeven">
  <p><input type="text" name="z11" value="" size="4" /> <span> Adjusted BMI </span></p>
  <p><input type="text" name="z12" value="" size="4" /> <span> Age in years </span></p>
  <p><input type="text" name="z13" value="" size="4" /> <span> Male or Female </span></p>
  <p><input type="text" name="result7" value="" size="4" /> <span> BF% </span></p>
  <p><input onclick="calculate7()" type="BUTTON" value="Calculate" /></p>
</form>

<script type="text/javascript">// 
function calculate7() {
  var x = document.formSeven.z11.value;
  var y = document.formSeven.z12.value;
  var z = document.formSeven.z13.value.toLowerCase();
  var r = document.formSeven.result7;
  r.value=(z=='female'?(x+y-5.4):(z=='male'?(x+y-16.2):r.value));
}
// ]]></script>

您还可以再清理一下代码

<form action="#" method="post" name="formSeven">
  <p><input type="text" name="z11" size="4" /> <span> Adjusted BMI </span></p>
  <p><input type="text" name="z12" size="4" /> <span> Age in years </span></p>
  <p><input type="text" name="z13" size="4" /> <span> Male or Female </span></p>
  <p><input type="text" name="result7" size="4" /> <span> BF% </span></p>
  <p><input onclick="calculate7()" type="button" value="Calculate" /></p>
</form>
<script type="text/javascript"> 
function calculate7() {
 var f=document.formSeven,
 x=f.z11.value,
 y=f.z12.value,
 z=f.z13.value.toLowerCase(),
 r=f.result7;
 r.value=(z=='female'?(x+y-5.4):(z=='male'?(x+y-16.2):r.value));
}
</script>

Answer 5

值是字符串，因此不是添加数字，而是连接字符串。

将字符串解析为数字：

var x = parseInt(document.formSeven.z11.value, 10);
var y = parseInt(document.formSeven.z12.value, 10);

请问我的IF报告可以帮到我吗？

5 个答案: