我目前正在尝试制作一个解决克雷默规则的项目，但是，我的 JS 没有打印到浏览器。这是我到目前为止所拥有的:
我想知道如何修改我的代码以打印到浏览器: 我使用了错误的方法吗？我应该使用“getElementById()”函数来获取值吗？在函数内声明类是否存在问题？
它只是写“document.write(“方程是:”);”在调用该函数之前，先将其添加到表单上方的文档中。
<!DOCTYPE html>
<html>
<head>
<title>Kremer's rule</title>
<link type="text/css" rel="stylesheet" href="stylesheet.css" />
<h1>Solve Kremer's Rule</h1>
<SCRIPT LANGUAGE="JavaScript">
function testResults (form) {
function system (x1, x2, x3, y1, y2, y3, z1, z2, z3, a1, a2, a3){
this.x1 = x1;
this.x2 = x2;
this.x3 = x3;
this.y1 = y1;
this.y2 = y2;
this.y3 = y3;
this.z1 = z1;
this.z2 = z2;
this.z3 = z3;
this.a1 = a1;
this.a2 = a2;
this.a3 = a3;
this.calcDanswer = function() {
return (this.x1*((this.y2*this.z3)-(this.z2*this.y3))) - (this.y1*((this.x2*this.z3)-(this.z2*this.x3))) + (this.z1*((this.x2*D.y3)- (this.y2*this.x3)));
};
this.calcXanswer = function(){
return (this.a1*((this.y2*this.z3)-(this.z2*this.y3))) - (this.y1*((this.a2*this.z3)-(this.z2*this.a3))) + (this.z1*((this.a2*this.y3)-(this.y2*this.a3)));
};
this.calcYanswer = function(){
return (this.x1*((this.a2*this.z3)-(this.z2*this.a3))) - (this.a1*((this.x2*this.z3)-(this.z2*this.x3))) + (this.z1*((this.x2*this.a3)-(this.a2*this.x3)));
};
this.calcZanswer = function(){
return (this.x1*((this.y2*this.a3)-(this.a2*this.y3))) - (this.y1*((this.x2*this.a3)-(this.a2*this.x3))) + (this.a1*((this.x2*this.y3)-(this.y2*this.x3)));
};
}
var x1 = form.x1.value;
var x2 = form.x2.value;
var x3 = form.x3.value;
var y1 = form.y1.value;
var y2 = form.y2.value;
var y3 = form.y3.value;
var z1 = form.z1.value;
var z2 = form.z2.value;
var z3 = form.z3.value;
var a1 = form.a1.value;
var a2 = form.a2.value;
var a3 = form.a3.value;
var D = new system(x1, x2, x3, y1, y2, y3, z1, z2, z3, a1, a2, a3);
var X = D.calcXanswer()/D.calcDanswer();
var Y = D.calcYanswer()/D.calcDanswer();
var Z = D.calcZanswer()/D.calcDanswer();
}
//printing to console
document.write("The equations are:");
document.write(D.x1 + "x + " + D.y1 + "y + " + D.z1 +"z = "+D.a1);
document.write(D.x2 + "x + " + D.y2 + "y + " + D.z2 +"z = "+D.a2);
document.write(D.x3 + "x + " + D.y3 + "y + " + D.z3 +"z = "+D.a3);
document.write("The answer for D is " + D.calcDanswer());
document.write("The answer for Dx is " + D.calcXanswer());
document.write("The answer for Dy is " + D.calcYanswer());
document.write("The answer for Dy is " + D.calcZanswer());
document.write();
document.write("X is " + X);
document.write("Y is " + Y);
document.write("Z is " + Z);
</SCRIPT>
</head>
<body>
<!--Explaination-->
<div>
<h2><span id="highlight">What this does</span></h2>
<p>Type in all the information for your system of three equations.<br />
When finished hit "Go".</p>
</div>
<!--Form-->
<div class="matrix">
<FORM NAME="myform" ACTION="" METHOD="GET">
<input type="text" name="x1"> x + <input type="text" name="y1"> y + <input type="text" name="z1"> z = <input type="text" name="a1"><br />
<input type="text" name="x2"> x + <input type="text" name="y2"> y + <input type="text" name="z2"> z = <input type="text" name="a2"><br />
<input type="text" name="x3"> x + <input type="text" name="y3"> y + <input type="text" name="z3"> z = <input type="text" name="a3"><br />
<INPUT TYPE="button" NAME="button" Value="Click" onClick="testResults(this.form)">
</form>
</div>
<!--Answer-->
<div id="answer">
<h1><span id="highlight">The Answer:</span></h2>
hiyhioiihhoihohhi<br/>
</div>
</body>
</html>
最佳答案
您的 D,X,Y,Z 变量是 testResults 的本地变量，并且您尝试在 testResults 之外使用它们。
您可能只想将 document.write 移动到 testResults 中，更好的是，操作 DOM，这样您就不会丢失其中的所有内容页面
function testResults (form) {
function system (x1, x2, x3, y1, y2, y3, z1, z2, z3, a1, a2, a3){
...
}
var x1 = form.x1.value;
var x2 = form.x2.value;
var x3 = form.x3.value;
var y1 = form.y1.value;
var y2 = form.y2.value;
var y3 = form.y3.value;
var z1 = form.z1.value;
var z2 = form.z2.value;
var z3 = form.z3.value;
var a1 = form.a1.value;
var a2 = form.a2.value;
var a3 = form.a3.value;
var D = new system(x1, x2, x3, y1, y2, y3, z1, z2, z3, a1, a2, a3);
var X = D.calcXanswer()/D.calcDanswer();
var Y = D.calcYanswer()/D.calcDanswer();
var Z = D.calcZanswer()/D.calcDanswer();
// printing to he apge
var out = document.getElementById('real-answer');
out.innerHTML += "The equations are:" +
D.x1 + "x + " + D.y1 + "y + " + D.z1 +"z = "+D.a1 +
D.x2 + "x + " + D.y2 + "y + " + D.z2 +"z = "+D.a2 +
D.x3 + "x + " + D.y3 + "y + " + D.z3 +"z = "+D.a3 +
"The answer for D is " + D.calcDanswer() +
"The answer for Dx is " + D.calcXanswer() +
"The answer for Dy is " + D.calcYanswer() +
"The answer for Dy is " + D.calcZanswer() +
"X is " + X +
"Y is " + Y +
"Z is " + Z;
}
关于JavaScript 不从 HTML 表单获取值，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/21743726/