CODEWITHSUNDEEP
javascriptjqueryarraysnode.js
Dalton2
Dalton2

Reputation: 135

How to extract value from an Array in Javascript

I am querying my db in node and have got the result in the form of an object like this - [ [1234] ].

I want to extract this value and convert it into a string and then pass it onto the client side. I have written the other required code but I am not able to get value from this object. Can anyone help me in getting the value and converting it to string?

Upvotes: 1

Views: 22950

Answers (5)

Rabi Ranjan
Rabi Ranjan

Reputation: 1

Using De-structuring Array concept:

const arr = [[1, 2, 3, 4, 5]];
const [[p, q, r, s, t]] = arr;
console.log(p, q, r, s, t);

Output: 1 2 3 4 5

Upvotes: 0

Sunali Bandara
Sunali Bandara

Reputation: 410

to extract values from a string array or an array we can use .toString()

Ex:

let names = ["peter","joe","harry"];
let fname = names.toString();
 output = peter ,joe,harry

or

 let name:string[] = this.customerContacts.map(
 res => res.firstname 
 let fname =name.toString();

Upvotes: 1

m87
m87

Reputation: 4523

Since, the result you've got is a two-dimensional array, you can get the value and convert it into a string (using toString() method) in the following way ...

var result = [ [1234] ];
var string;
result.forEach(function(e) {
  string = e.toString();
});
console.log(string);

** this solution will also work if you have multiple results, ie. [ [1234], [5678] ]

Upvotes: 4

dodov
dodov

Reputation: 5844

You have a nested array, meaning that you have an array inside another array:

   [ [1234] ]
// ^-^====^-^

To get the first value of the parent array, use the square brackets: [0]. Remember that indexes start at 0!

If you have val = [[1234]], val[0] gets the enclosed array: [1234]. Then, 1234 is a value in that array (the first value), so you use the square brackets again to get it: val[0][0].

To convert to string, you can use + "" which forces the number to become a string, or the toString() method.

var val = [[1234]];
var str = val[0][0] + "";
//     or val[0][0].toString();

console.log(str, typeof str);

You can read more about arrays here.

Upvotes: 2

Ngoan Tran
Ngoan Tran

Reputation: 1527

var response = [ [1234] ];
console.log(response[0][0]);

Upvotes: 1

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