jQuery Window Width else if语句 [英] jQuery Window Width else if statement

问题描述

我想知道为什么我的最后一个if语句永远不会被执行。我想这样做：

I am wondering why my last else if statement never gets executed. I am trying to do this:

$(document).ready(function() {
    function checkWidth() {
        var windowSize = $(window).width();

        if (windowSize <= 479) {
            console.log("screen width is less than 480");
        }
        else if (windowSize = 480 && windowSize <= 719) {
            console.log("screen width is less than 720 but greater than or equal to 480");
        }
        else if (windowSize = 720 && windowSize <= 959) {
            console.log("screen width is less than 960 but greater than or equal to 720");
        }
        else if (windowSize >= 960) {
            console.log("screen width is greater than or equal to 960");
        }
    }

    // Execute on load
    checkWidth();
    // Bind event listener
    $(window).resize(checkWidth);
});​

一切都得到了在控制台中ogged除了最后的其他if。我做错了什么？

Everything gets logged in the console except for the last else if. What am I doing wrong?

谢谢，

更新：

对于仍然感兴趣的人，我强烈推荐enquire.js插件：

For anyone still interested, I highly recommend the enquire.js plugin:

http://wicky.nillia.ms/enquire.js/

放下最好的方法我发现在JS中识别媒体查询。

Hands down best approach I've found to recognizing media queries in JS.

推荐答案

你错过了一对> = 在你的代码中，并且没有比较windowSize，但是由于 windowSize = 480 等语句而分配了一个新值。请尝试使用此版本：

You are missing a couple >= in your code, and windowSize is not being compared but assigned a new value as a result of statements like windowSize = 480. Try this version instead:

$(document).ready(function() {
    function checkWidth() {
        var windowSize = $(window).width();

        if (windowSize <= 479) {
            console.log("screen width is less than 480");
        }
        else if (windowSize <= 719) {
            console.log("screen width is less than 720 but greater than or equal to 480");
        }
        else if (windowSize <= 959) {
            console.log("screen width is less than 960 but greater than or equal to 720");
        }
        else if (windowSize >= 960) {
            console.log("screen width is greater than or equal to 960");
        }
    }

    // Execute on load
    checkWidth();
    // Bind event listener
    $(window).resize(checkWidth);
});​

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