Javascript pythagoras函數顯示爲undefined

Question

我是初學者，不明白爲什麼以下顯示爲undefined。

以下是我的腳本：

function pythagoras() { 
    function solvepy(form) { 
     var a = parseFloat(form.a.value); 
     var b = parseFloat(form.b.value); 
     c.value = Math.sqrt(a * a + b * b); 
    } 

    function pythagoras(form) { 
     var aInput = document.getElementById("a"); 
     var bInput = document.getElementById("b"); 
    } 
    var result = displayResult(); 
} 

function displayResult(a, b, c) { 
    var div = document.getElementById("result"); 
    div.innerHTML = "Triangle: a = " + a + ", b = " + b + ". c = " + c; 
} 

以下是我的身體：

<form> 
    <label for="a">Enter lengths for sides a: </label> 
    <input type="number" id="a" size="3"> 
    <label for="b"> and b: </label> 
    <input type="number" id="b" size="3"><br> 
    <input type="button" id="submit" value="Compute c!"> 
</form> 
<div id="result"> 
</div> 

Answer 1

試試這個..

的Javascript：

// Set global variables, so they can be accessed trough all functions 
var a, b, c; 

function calculate() { 
     a = parseFloat(document.pythagora.a.value); 
     b = parseFloat(document.pythagora.b.value); 
     c = Math.sqrt(a * a + b * b); 
     displayResult(a,b,c); 
} 
function displayResult(a, b, c) { 
    var div = document.getElementById("result"); 
    div.innerHTML = "Triangle: a = " + a + ", b = " + b + ". c = " + c; 
} 

身體

<form name="pythagora"> 
    <label for="a">Enter lengths for sides a: </label> 
    <input type="number" id="a" size="3"> 
    <br> 
    <label for="b"> and b: </label> 
    <input type="number" id="b" size="3"><br> 
    <br> 
    <input type="button" id="submit" value="Compute c!" onClick="calculate();"> 
</form> 
<div id="result"> 
</div> 

Here is a working example link..(click here)