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"}
    */