先看下需求。
我想把这很长一大段的带有markdown格式的字符串里包含的image标签的文件名和url解析出来,连同文件名中包含的序号,一起存储到一个数组中。
var input = “” + “\n” +
“” + “\n” +
“”;
然后对这个数组根据序号进行排序,比如上图的image标签顺序是image3, image1和image2,但我希望排序后的顺序是image1, image2和image3.
下面是我的代码。
<html> <script> var input = "![image3.png](https://upload-images.jianshu.io/upload_images/2085791-4d8b2cda3a057fb6.png?imageMogr2/auto-orient/strip%7CimageView2/2/w/1240)" + "\n" + "![image1.png](https://upload-images.jianshu.io/upload_images/2085791-9aa6232b1426df28.png?imageMogr2/auto-orient/strip%7CimageView2/2/w/1240)" + "\n" + "![image2.png](https://upload-images.jianshu.io/upload_images/2085791-04f2773c126194fe.png?imageMogr2/auto-orient/strip%7CimageView2/2/w/1240)"; var IMAGE_PATTERN = /^!\[(.*)\]\((.*)\)$/; var IMAGE_INDEX = /^image(\d+).*$/; function MyImage(index, name, url){ this.index = index; this.name = name; this.url = url; } var imagePool = []; function sortByIndex(v1,v2){ if(v1.index < v2.index ){ return -1; } else if(v1.index > v2.index ){ return 1; } else return 0; } function getParsedImage(input) { if (input.indexOf("https://upload-images.jianshu.io") < 0 ) { return; } var result = IMAGE_PATTERN.exec(input); if( result.length != 3){ return; } var imageIndex = IMAGE_INDEX.exec(result[1]); console.assert(imageIndex.length === 2); return new MyImage(imageIndex[1], result[1], result[2]); } var raw = input.split("\n"); for( var i = 0; i < raw.length; i++){ var each = getParsedImage(raw[i]); if( !!each){ imagePool.push(each); } } imagePool.sort(sortByIndex); debugger; </script> </html>
第58行传入数组原生的sort方法的参数是一个排序函数:
执行完之后,就按照我期望的MyImage对象里index属性进行排序了: