js数组

变异方法 (mutation method)

push( { message: 'Baz' })    pop()    shift()    unshift( { message: 'Baz' })    splice(0,1, { message: 'Baz' }    sort()    reverse()

含义 向数组的末尾添加一个或更多元素，并返回新的长度 删除并返回数组的最后一个元素 删除并返回数组的第一个元素 向数组的开头添加一个或更多元素，并返回新的长度 删除元素，并向数组添加新元素 对数组的元素进行排序 颠倒数组中元素的顺序
items前 "items: [
{ message: 'Foo' },
{ message: 'Bar' }
]" "items: [
{ message: 'Foo' },
{ message: 'Bar' }
]" "items: [
{ message: 'Foo' },
{ message: 'Bar' }
]" "items: [
{ message: 'Foo' },
{ message: 'Bar' }
]" "items: [
{ message: 'Foo' },
{ message: 'Bar' }
]" "items: [
{ message: 'Foo' },
{ message: 'Bar' }
]" "items: [
{ message: 'Foo' },
{ message: 'Bar' }
]"
返回值 3 { message: 'Bar' } { message: 'Foo' } 3 [ { message: 'Foo' }] " [
{ message: 'Foo' },
{ message: 'Bar' }
]" " [
{ message: 'Bar' },
{ message: 'Foo' }
]"
items后 "items: [
{ message: 'Foo' },
{ message: 'Bar' },
{ message: 'Baz' }
]" "items: [
{ message: 'Foo' },
]" "items: [
{ message: 'Bar' }
]" "items: [
{ message: 'Baz' },
{ message: 'Foo' },
{ message: 'Bar' }
]" "items: [
{ message: 'Baz' }
{ message: 'Bar' }
]" "items: [
{ message: 'Foo' },
{ message: 'Bar' }
]" "items: [
{ message: 'Bar' },
{ message: 'Foo' }
]"

非变异方法(non-mutating method)

filter()    concat()    slice(1)

含义 连接两个或更多的数组，并返回结果
items前 "items: [
{ message: 'Foo' },
{ message: 'Bar' }
]" "items: [
{ message: 'Foo' },
{ message: 'Bar' }
]" "items: [
{ message: 'Foo' },
{ message: 'Bar' }
]"
返回值 " [
{ message: 'Foo' },
{ message: 'Bar' },
{ message: 'Baz' }
]" [ { message: 'Bar' }]
items后 "items: [
{ message: 'Foo' },
{ message: 'Bar' }
]" "items: [
{ message: 'Foo' },
{ message: 'Bar' }
]" "items: [
{ message: 'Foo' },
{ message: 'Bar' }
]"