数组的对象元素，按照对象的某个键分类，把键的值相同的放到一个数组里，生成一个新的二维数组

数组排序与分类

原创已于 2022-01-18 17:36:00 修改 · 624 阅读

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文章标签：

#分类 #排序算法 #算法 #javascript

于 2022-01-18 17:20:52 首次发布

本文介绍了一种使用JavaScript对数组进行排序的方法，并进一步实现按特定属性值进行分类的技术。通过示例代码展示了如何先对对象数组根据指定字段进行排序，再将相同属性值的对象归为一组。

基础：数组的sort方法

 let arr = [
 { name: "xue", age: "li" }, { name: "zhong", age: "wang" },
 { name: "han", age: "liu" }, { name: "dao", age: "wang" },
 { name: "xing", age: "wang" }, { name: "cheng", age: "zhang" },
 { name: "feng", age: "li" }, { name: "nian", age: "li" },
 { name: "jiang", age: "liu" }, { name: "ni", age: "liu" },
 { name: "xu", age: "zhang" }, { name: "xiao", age: "zhang" }
 ]
 let arr2 = arr.sort(function (a, b) {
     var s = a["age"],
         t = b["age"];
      return s < t ? -1 : 1;
   });
 console.log(arr2);

结果：在这里插入图片描述
分类

function sortArr(arr, str) {
            var _arr = [],
                _t = [],
                // 临时的变量
                _tmp;
            // 按照特定的参数将数组排序将具有相同值得排在一起
            arr = arr.sort(function (a, b) {
                var s = a[str],
                    t = b[str];

                return s < t ? -1 : 1;
            });

            if (arr.length) {
                _tmp = arr[0][str];
            }
            // 将相同类别的对象添加到统一个数组
            for (var i in arr) {
                if (arr[i][str] === _tmp) {
                    _t.push(arr[i]);
                } else {
                    _tmp = arr[i][str];
                    _arr.push(_t);
                    _t = [arr[i]];
                }
            }
            // 将最后的内容推出新数组
            _arr.push(_t);
            return _arr;
        }
        let arr = [
         { name: "xue", age: "18" }, { name: "zhong", age: "18" }, 
         { name: "han", age: "19" }, { name: "dao", age: "19" }, 
         { name: "xing", age: "19" },{ name: "cheng", age: "19" },
         { name: "feng", age: "20" }, { name: "nian", age: "20" }, 
         { name: "jiang", age: "18" }, { name: "ni", age: "19" }, 
         { name: "xu", age: "20" }, { name: "xiao", age: "18" }
         ]
        let arr2 = sortArr(arr, "age")
        console.log(arr2);