map

    var arr1 = [
        { name: '鸣人', age: 16 },
        { name: '佐助', age: 17 }
    ];

新增选项money，值为520，不改变原数组值arr1

    let a = arr1.map(item => {
        return { ...item, money: 520 }
    })
    console.log(a)
    console.log(arr1)

image.png

删除age属性，，不改变原数组值arr1

    let a = arr1.map(item => {
        const { age, ...rest } = item
        // return rest
        return { ...rest }
    })
    console.log(a)
    console.log(arr1)

image.png

改age属性的值为999，不改变原数组值arr1

    let a = arr1.map(item => {
        return { ...item, age: 999 }
    })
    console.log(a)
    console.log(arr1)

image.png

查name为[鸣人]，把他的年龄变成99，不改变原数组值arr1

    let a = arr1.map(item => {
        if (item.name == '鸣人') {
            return { ...item, age: 999 }
        }
        return item
    })
    console.log(a)
    console.log(arr1)

image.png

把属性age，变成agegege

    let a = arr1.map(item => {
        return { ...item, 'agegege': item['age'] }
    }).map(item => {
        const { age, ...rest } = item
        return rest
    })
    console.log(a)
    console.log(arr1)

image.png