javascript - 识别不同类型的三 Angular 形

Question

我正在尝试编写代码来识别不同类型的三 Angular 形。但是当功能被激活时，没有警报。这是我的代码:

function alertf(){
            var a=document.getElementById("a").value;
            var b=document.getElementById("b").value;
            var c=document.getElementById("c").value;
            if((sqr(a)+sqr(b)==sqr(c))||(sqr(a)+sqr(c)==sqr(b))||(sqr(b)+sqr(c)==sqr(a))) 
                     alert("Right triangle")                                                
            else if((a==b)||(b==c)||(a==c)) alert("Isosceles triangle")
                else if((a==b)&&(a==c)) alert("Equilateral triangle")
                  else alert("Ordinary triangle");

Answer 1

我会尝试以下方法:

function sqr(x) {
    return Math.pow(x, 2);
}

function showOutput(output) {
    document.getElementById("output").innerHTML = output;
}

function alertf(){
    var a = document.getElementById("a").value;
    var b = document.getElementById("b").value;
    var c = document.getElementById("c").value;

    if((sqr(a)+sqr(b)==sqr(c))||(sqr(a)+sqr(c)==sqr(b))||(sqr(b)+sqr(c)==sqr(a))) {
        showOutput("Right triangle");
    } else if((a==b)&&(a==c)) {
        showOutput("Equilateral triangle");
    } else if((a==b)||(b==c)||(a==c)) {
        showOutput("Isosceles triangle");
    } else {
        showOutput("Ordinary triangle");
    }
}

alertf();

Side A length: <input id="a" value="3" onchange="alertf()"></input><br>
Side B length: <input id="b" value="4" onchange="alertf()"></input><br>
Side C length: <input id="c" value="5" onchange="alertf()"></input><br><br>
Output:<div id="output"><div>