数组的各种操作

数组的操作

序号	操作	备注
1	获取数组最大(最小)值
2	获取数组最大值
3	获取数组最大值

1. 获取数组最大(最小)值

   
   

   Math.max(...arr1) 和 Math.min(...arr1) 方法

   
   let arr1 = [8, 4, 7, '52', 6, 9, 3, '2']
   let maxNumber = Math.max(...arr1)
   let minNumber = Math.min(...arr1)
   console.log('最大值：', maxNumber);// 52
   console.log('最小值：', minNumber);// 2
               

   arr2.reduce 方法

     
   let arr2 = [
       {
         age: "12",
         name: "张三",
       }, {
         age: 46,
         name: "李四",
       }, {
         age: 8,
         name: "王五",
       },
       {
         age: "34",
         name: "赵六",
       },
   ]
   let bigest = arr2.reduce((p, v) => p.age < v.age ? v : p)
   let smallest = arr2.reduce((p, v) => p.age > v.age ? v : p)
   let totalAge = arr2.reduce((accumulator, currentValue, currentIndex, array) => {
       	return accumulator + parseFloat(currentValue.age)
   }, 0)
   console.log('最大值：', bigest); //  {age: 46, name: "李四"}
   console.log('最小值：', smallest); //  {age: 8, name: "王五"}
   console.log('年龄总的加起来：', parseFloat(totalAge).toFixed(2)); // 100.00
               

   arr3.sort(compare) 方法

     
   function compare(a, b) {
       return a - b ;//升序
       // return b - a ;//降序
   }
   let arr3 = [5, 24, 32, '14', 6, '6', 14]
   let _arr3 = arr3.sort(compare)
   console.log('排序：_arr3 :', _arr3)
   console.log('最小值 :', _arr3[0], '】【最大值 :', _arr3[_arr3.length - 1])
               

   compare(property) 对象内的值 比较

   
   let arr_3 = [{
           age: "12",
           name: "张三",
       }, {
           age: 46,
           name: "李四",
       }, {
           age: 8,
           name: "王五",
       },
       {
           age: "34",
           name: "赵六",
       },
   ]
   function compare(property) {
   
   return function(a, b) {
   
   return a[property] - b[property]; //升序
   
   // return b[property] - a[property]; //降序
   
   }
   
   }
   
   let _arr_3 = arr_3.sort(compare('age'))
   
   console.log('_arr_3:', _arr_3)
   
   /*
   
   0: {age: 8, name: "王五"}
   
   1: {age: "12", name: "张三"}
   
   2: {age: "34", name: "赵六"}
   
   3: {age: 46, name: "李四"}
   
   */