从 html 调用 javascript 对象方法

问题描述：

我对 Javascript 编程比较陌生.我正在编写一个示例，但在从 HTML 调用对象上的方法时遇到困难.我怀疑这与方法的范围或外化有关，但我不确定.

I'm relatively new to Javascript programming. I'm working on an example and am having difficulty in invoking a method on an object from HTML. I suspect this has something to do with the scoping or externalization of the methods, but I'm not sure.

index.html:

<script type="text/javascript">
var f = new Fred();
f.bar();
f.foo();
</script>

Fred.js:

function Fred() {
this.a = 1;

function foo() {
    if (a == 1) {
        a++;
    } 
    var e = 0;
}

this.bar = function () {
    var a = 3;
    var b = 4;
};

this.c = 3;
this.d = 4;

}

对 bar() 的调用有效，对 foo() 的调用无效.

The call to bar() works, the call to foo() does not.

答

您没有分配函数指针指向 foo.改成

your not assigning a function pointer to foo. Change it to

this.foo = function() {
    if (a == 1) {
        a++;
    } 
    var e = 0;
};

就像你所做的那样:

this.bar = function () {
    var a = 3;
    var b = 4;
};

从 html 调用 javascript 对象方法

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