变量名前的美元符号或没有美元符号 [英] Dollar sign in front of a variable name or no dollar sign

问题描述

我正在阅读Scott Allen的有关ASP.NET MVC的教程.我到了一些使用jQuery的代码的部分.

I'm going through Scott Allen's tutorial about ASP.NET MVC. I got to the section where there is some code that uses jQuery.

$(function () {
    var ajaxFormSubmit = function () {
        var $form = $(this);
        var options = {
            url: $form.attr("action"),
            type: $form.attr("method"),
            data: $form.serialize()
        };
        $.ajax(options).done(function (data) {
            var $target = $($form.attr("data-otf-target"));
            var $newHtml = $(data);
            $target.replaceWith($newHtml);
            $newHtml.effect("highlight");
        });
        return false;
    };

我试图了解带有或不带有美元符号的变量之间的区别.例如，变量form具有美元符号，而options没有美元符号，那么ajax done部分中的变量也具有美元符号.

I'm trying to understand what's the difference between the variables with or without the dollar signs. For example variable form has a dollar sign and the options does not and then the variables inside the ajax done part also have the dollar signs.

在我们使用jQuery的系统中，我没有看到这样的代码.有什么区别?这与ASP.NET MVC 4和/或新版本的jQuery有关吗?

In our system where we use jQuery I haven't seen such code. What is the difference? Is this has something to do with the ASP.NET MVC 4 and/or the new versions of jQuery?

推荐答案

$在JavaScript标识符中没有特殊含义.

$ has no special meaning in a JavaScript identifier.

有一个惯例可以使用以$字符开头的变量名来表示将包含jQuery对象的变量.

There is a convention to use a variable name starting with a $ character to represent a variable that will hold a jQuery object.

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