绝对让你想不通的问题(1.08+0.34) != 1.42 为真

Question

<script>
var qnqy = 1.42;
        
if ((parseFloat(1.08) + parseFloat(0.34)) != parseFloat(qnqy)) {
     document.write("no<br/>");
document.write(parseFloat(1.08)+"<br/>");
document.write(parseFloat(0.34)+"<br/>");
document.write((1.08+0.34)==1.42?"yes":"no");
        }else{
            document.write("yes");
        }
</script>
大家看下是什么原因啊,急!

Answer 1

document.write((1.08+0.34).toString() + "<br/>");
document.write(1.42.toString());
//这样你就清楚了

Answer 2

结果还是no啊
var qnqy = 1.42;
        
if ((parseFloat(1.08) + parseFloat(0.34)).toString() != qnqy.toString()) {
     document.write("no<br/>");
document.write(parseFloat(1.08)+"<br/>");
document.write(parseFloat(0.34)+"<br/>");
document.write((1.08+0.34)==1.42?"yes":"no");
document.write((1.08)==1.08?"yes":"no");
        }else{
            document.write("yes");
        }

Answer 3

document.write((1.08+0.34).toFixed(2)==1.42?"yes":"no");
//(1.08+0.34).toFixed(2)四舍五入，只取小数点后2位，然后比较

Answer 4

感谢
但是为什么document.write((1.08+0.34))结果是1.42啊,为什么取了2位小数后就正确了?,还有如果是var hj1 = 0;
        var hj2 = 1.08;
        var hj3 = 1;
        var hj4 = 0.34;
        var hj5 = 0;        var qnqy = 2.42;
        //结果是yes
        if ((hj1+hj2+hj3+hj4+hj5) != qnqy) {
     document.write("no<br/>");
}else{
            document.write("yes");
        }
        //结果是no
        if ((hj1+hj2+hj4+hj5) != qnqy) {
     document.write("no<br/>");
}else{
            document.write("yes");
        }

Answer 5

打错了var hj1 = 0;
        var hj2 = 1.08;
        var hj3 = 1;
        var hj4 = 0.34;
        var hj5 = 0;        var qnqy = 2.42;
var qnqy1 = 1.42;
        //结果是yes
        if ((hj1+hj2+hj3+hj4+hj5) != qnqy) {
            document.write("no<br/>");
    }else{
            document.write("yes");
        }
        //结果是no
        if ((hj1+hj2+hj4+hj5) != qnqy1) {
            document.write("no<br/>");
    }else{
            document.write("yes");
        }