小技巧 – 做一个，个性化的Console

现在的浏览器都有开发者工具（F12呼出），其中有一个相当重要的面板——Console，用它可以实现查看错误信息、打印调试信息、调试js代码等功能。我们可以用Console备注一些特殊信息或者彩蛋。

添加Console
其实想要添加一个Console很简单，只需在你想要展示的页面内包含以下内容即可（想要全站显示，可以放到head内）

<script>
    console.log("展示内容1");
    console.log("展示内容2");
    console.log("展示内容3");
</script>

这样在前端Console中输出的信息就是展示内容这些纯文字内容。想要更加的个性化，需要CSS的支持，好在现代浏览器已经支持部分CSS样式在Console内的应用。

n可以用来换行；%c用来标记之后的内容使用对应样式，格式：console.log(“%c内容1%c内容2″,”CSS1″,”CSS2”);

示例：

<script>
    console.log("%c展示内容1", "font-size:14px;color:red;");
    console.log("%c展示内容2\n换行演示", "font-size:14px;color:red;");
    console.log("%c展示%c内容3\n%c换行多CSS演示", "font-size:14px;color:red;", "font-size:18px;color:green;", "font-size:16px;color:blue;");
</script>

可用的格式符和CSS不止这些

下面是console.log() API的官方文档摘要。

谷歌开发者中心上面关于谷歌浏览器控制台console.log()的文档：
Format Specifier Description
%s Formats the value as a string.
%d or %i Formats the value as an integer.
%f Formats the value as a floating point value.
%o Formats the value as an expandable DOM element (as in the Elements panel).
%O Formats the value as an expandable JavaScript object.
%c Formats the output string according to CSS styles you provide.

1.3D Text:

console.log("%c3D Text"," text-shadow: 0 1px 0 #ccc,0 2px 0 #c9c9c9,0 3px 0 #bbb,0 4px 0 #b9b9b9,0 5px 0 #aaa,0 6px 1px rgba(0,0,0,.1),0 0 5px rgba(0,0,0,.1),0 1px 3px rgba(0,0,0,.3),0 3px 5px rgba(0,0,0,.2),0 5px 10px rgba(0,0,0,.25),0 10px 10px rgba(0,0,0,.2),0 20px 20px rgba(0,0,0,.15);font-size:5em")

2.Colorful CSS

console.log("%cColorful CSS","background: rgba(252,234,187,1);background: -moz-linear-gradient(left, rgba(252,234,187,1) 0%, rgba(175,250,77,1) 12%, rgba(0,247,49,1) 28%, rgba(0,210,247,1) 39%,rgba(0,189,247,1) 51%, rgba(133,108,217,1) 64%, rgba(177,0,247,1) 78%, rgba(247,0,189,1) 87%, rgba(245,22,52,1) 100%);background: -webkit-gradient(left top, right top, color-stop(0%, rgba(252,234,187,1)), color-stop(12%, rgba(175,250,77,1)), color-stop(28%, rgba(0,247,49,1)), color-stop(39%, rgba(0,210,247,1)), color-stop(51%, rgba(0,189,247,1)), color-stop(64%, rgba(133,108,217,1)), color-stop(78%, rgba(177,0,247,1)), color-stop(87%, rgba(247,0,189,1)), color-stop(100%, rgba(245,22,52,1)));background: -webkit-linear-gradient(left, rgba(252,234,187,1) 0%, rgba(175,250,77,1) 12%, rgba(0,247,49,1) 28%, rgba(0,210,247,1) 39%, rgba(0,189,247,1) 51%, rgba(133,108,217,1) 64%, rgba(177,0,247,1) 78%, rgba(247,0,189,1) 87%, rgba(245,22,52,1) 100%);background: -o-linear-gradient(left, rgba(252,234,187,1) 0%, rgba(175,250,77,1) 12%, rgba(0,247,49,1) 28%, rgba(0,210,247,1) 39%, rgba(0,189,247,1) 51%, rgba(133,108,217,1) 64%, rgba(177,0,247,1) 78%, rgba(247,0,189,1) 87%, rgba(245,22,52,1) 100%);background: -ms-linear-gradient(left, rgba(252,234,187,1) 0%, rgba(175,250,77,1) 12%, rgba(0,247,49,1) 28%, rgba(0,210,247,1) 39%, rgba(0,189,247,1) 51%, rgba(133,108,217,1) 64%, rgba(177,0,247,1) 78%, rgba(247,0,189,1) 87%, rgba(245,22,52,1) 100%);background: linear-gradient(to right, rgba(252,234,187,1) 0%, rgba(175,250,77,1) 12%, rgba(0,247,49,1) 28%, rgba(0,210,247,1) 39%, rgba(0,189,247,1) 51%, rgba(133,108,217,1) 64%, rgba(177,0,247,1) 78%, rgba(247,0,189,1) 87%, rgba(245,22,52,1) 100%);filter: progid:DXImageTransform.Microsoft.gradient( startColorstr='#fceabb', endColorstr='#f51634', GradientType=1 );font-size:5em")

3.Rainbow Text

console.log('%cRainbow Text ', 'background-image:-webkit-gradient( linear, left top, right top, color-stop(0, #f22), color-stop(0.15, #f2f), color-stop(0.3, #22f), color-stop(0.45, #2ff), color-stop(0.6, #2f2),color-stop(0.75, #2f2), color-stop(0.9, #ff2), color-stop(1, #f22) );color:transparent;-webkit-background-clip: text;font-size:5em;');

更新：在Chrome控制台输出图片
除了上面介绍的那些炫目的文字效果外，你还可以在Chrome控制台中显示图片,自然地，显示gif这样的动态图片也是没问题的。

还是应用差不多的代码，只是将内容变成指定背景为图片。

下面是一个例子：

console.log("%c", "padding:50px 300px;line-height:120px;background:url('https://cdn.jsdelivr.net/gh/cy-i/[email protected]/logo.png') no-repeat;");

是不是很简单，快去动手折腾吧！（想看我的自己F12?）