javascript - 用于计算 bmr 的 if else 语句

Question

我正在开展一个涉及计算 bmr 的学校项目，当我调用此函数时，我不断收到引用错误。

<script>
function calbmr(){
        var height, weight, age;
        var gender;

        age = parseFloat(document.bmiform.age.value)
        height = parseFloat(document.bmiform.height.value);
        weight = parseFloat(document.bmiform.weight.value);

        if (document.getElementById('Male').checked) {
             gender = (66 + (9.6 * weight) + (1.8 * height) – (4.7 * age));
             alert(gender);
         }  


        else if (document.getElementById('Female').checked) {
                 gender = (655 + (13.7 * weight) + (5 * height) – (6.8 * age));
                 alert(gender);
        }

        else {

            alert("please select a gender");
        }
    }
</script>       

但是当我将代码更改为它时，它会返回结果

if (document.getElementById('Male').checked) {
             gender = "Male"
             alert(gender);
         }  


        else {
            if (document.getElementById('Female').checked) {
                 gender = "Female";
                 alert(gender);
        }

Answer 1

您的代码中有两个错误的 - 符号:

if (document.getElementById('Male').checked) {
    gender = (66 + (9.6 * weight) + (1.8 * height) - (4.7 * age));
    //                                             ^
    alert(gender);
} else if (document.getElementById('Female').checked) {
    gender = (655 + (13.7 * weight) + (5 * height) - (6.8 * age));
    //                                             ^
    alert(gender);
}