如何在 javascript 中的一个数组中合并另一个数组对象中的数组

Question

I am looking to merge array inside another array objects in one array in javascript. I tried many way like concat and join methods but I couldn't get it I have array below array which I need to merge into one array

  arr =  [
        [{
                PRODUCE: 'Apple',
                STATE: 'CA',
                COUNTRY: 'US'
            },
            {
                PRODUCE: 'Apple',
                STATE: 'CA',
                COUNTRY: 'US'
            }
        ],
        [{
            PRODUCE: 'Apple',
            STATE: 'CP',
            COUNTRY: 'US'
        }]

    ]

I want result as below

[
    {
        PRODUCE: 'Apple',
        STATE: 'CA',
        COUNTRY: 'US'
    },
    {
        PRODUCE: 'Apple',
        STATE: 'CA',
        COUNTRY: 'US'
    },
    {
        PRODUCE: 'Apple',
        STATE: 'CP',
        COUNTRY: 'US'
    }
]

Answer 1

You can use flat() for this

The flat() method creates a new array with all sub-array elements concatenated into it recursively up to the specified depth.

Here you can read more about it

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/flat

 const arr = [ [{ PRODUCE: 'Apple', STATE: 'CA', COUNTRY: 'US' }, { PRODUCE: 'Apple', STATE: 'CA', COUNTRY: 'US' } ], [{ PRODUCE: 'Apple', STATE: 'CP', COUNTRY: 'US' }] ] console.log(arr.flat());

Answer 2

You can use Array.flat() .

var newArray = arr.flat([depth]);

 const arr = [ [{ PRODUCE: 'Apple', STATE: 'CA', COUNTRY: 'US' }, { PRODUCE: 'Apple', STATE: 'CA', COUNTRY: 'US' } ], [{ PRODUCE: 'Apple', STATE: 'CP', COUNTRY: 'US' }] ] console.log(arr.flat())

Answer 3

If you are able to use modern javascript, you can try:

arr.flat()

More info here: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/flat

If not, you can just use lodash, underscore or ramda. Libraries with useful utilities.

https://lodash.com/docs/4.17.15#flatten

Answer 4

There are two flat() answer, but alternative code that you tried for concat(), you can try like this:

 var arr = [ [{ PRODUCE: 'Apple', STATE: 'CA', COUNTRY: 'US' }, { PRODUCE: 'Apple', STATE: 'CA', COUNTRY: 'US' } ], [{ PRODUCE: 'Apple', STATE: 'CP', COUNTRY: 'US' }] ] var newArray = arr[1].concat(arr[0]); console.log(newArray);

Answer 5

Simple Approach, using spread operator and forEach loop

 const arr = [ [{ PRODUCE: 'Apple', STATE: 'CA', COUNTRY: 'US' }, { PRODUCE: 'Apple', STATE: 'CA', COUNTRY: 'US' } ], [{ PRODUCE: 'Apple', STATE: 'CP', COUNTRY: 'US' }] ] let result = []; arr.forEach((item)=>{ if(Array.isArray(item)){ result = [...result,...item] } else{ result = [...result,item] } } ) console.log(result)