javascript - 为什么这些 JavaScript 函数只有一个起作用？

Question

我有这个 JavaScript:

function Pythag1(){
var inputa = document.getElementById("input1");
var a = inputa.value;
var inputb = document.getElementById("input2");
var b = inputb.value;
if (b == "" || c == "" || isNaN(c) || isNaN(b)){
    alert("Try again!");
    }
else{
    alert("C=" + Math.sqrt((a*a) + (b*b)));
    }
}
/*above does not work*/


function Pythag2(){
var inputbc = document.getElementById("input3");
var sb = inputb.value;
var inputc = document.getElementById("input4");
var c = inputc.value;
if (sb == "" || c == "" || isNaN(c) || isNaN(sb) || (sb > c)){
    alert("Try again!");
    }
else{
    alert("A=" + Math.sqrt((c*c) - (sb*sb)));
    }
}

和 HTML:

<h3 style="text-align:left;">Pythagorean Theorem 1</h3>
<form>
A=<input type="text" id="input1" value="" name="aval" /><br />
B=<input type="text" id="input2" value="" name="bval" /><br />
<input type="submit" onclick="Pythag1()" />
</form>
<h3 style="text-align:left;">Pythagorean Theorem 2</h3>
<form>
B=<input type="text" id="input3" value="" name="bval2" /><br />
C=<input type="text" id="input4" value="" name="cval" /><br />
<input type="submit" onclick="Pythag2()" />
</form>

Pythag2() 函数有效，但 Pythag1() 无效。有什么想法吗？

Answer 1

您在 if 条件中使用的 c 变量似乎没有在任何地方定义。也许您的意思是:

function Pythag1() {
    var inputa = document.getElementById("input1");
    var a = parseFloat(inputa.value);
    var inputb = document.getElementById("input2");
    var b = parseFloat(inputb.value);
    if (isNaN(a) || isNaN(b)) {
        alert("Try again!");
    } else {
        alert("C=" + Math.sqrt((a * a) + (b * b)));
    }
}