I have an array as follows in nodejs

 var dataary=[];
    dataary=[ [ 'reg_no', 'slno', 'name', 'email', 'rollno' ],
    [ 'int', 'int', 'varchar', 'varchar', 'int' ],
    [ '100', '11', '255', '255', '100' ] ]

I need the count of array elements.As i do dataary.length it will return 3. But i need the count as 5 (count of elements inside array).How can i get the count of elements. ?

I have an array as follows in nodejs

 var dataary=[];
    dataary=[ [ 'reg_no', 'slno', 'name', 'email', 'rollno' ],
    [ 'int', 'int', 'varchar', 'varchar', 'int' ],
    [ '100', '11', '255', '255', '100' ] ]

I need the count of array elements.As i do dataary.length it will return 3. But i need the count as 5 (count of elements inside array).How can i get the count of elements. ?

• javascript
• node.js

• Wele to Stack Overflow! Please take the tour and read through the help center, in particular How do I ask a good question? Do your research, search for related topics on SO, and give it a go. If you get stuck and can't get unstuck after doing more research and searching, post a minimal reproducible example of your attempt and say specifically where you're stuck. People will be glad to help. Good luck! – T.J. Crowder Commented Dec 19, 2017 at 11:13
• 1 use dataary[0].length. – Vipin Kumar Commented Dec 19, 2017 at 11:14
• 1 Note: It just so happens that the length is 5 for all of the arrays in dataary, but it could just as easily be that they each had different lengths. – T.J. Crowder Commented Dec 19, 2017 at 11:14
• But i need the count of elements inside each array - loop through the main array and extract the length of each sub array? - stackoverflow./questions/12502843/… – Nope Commented Dec 19, 2017 at 11:17
• 1 But i need the count as 5 You need to get answer as 5 or 15? – Shalitha Suranga Commented Dec 19, 2017 at 11:17

3 Answers 3

With map you can get all lengths in one array and then you can sum them or do whatever you want to do.

var allLengths = dataary.map(element => {
   return element.length;
});

Iterate through loop and get length of each individual array .The forEach() method executes a provided function once for each array element.

var dataary=[];
    dataary=[ [ 'reg_no', 'slno', 'name', 'email', 'rollno' ],
    [ 'int', 'int', 'varchar', 'varchar', 'int' ],
    [ '100', '11', '255', '255', '100' ] ,
    [ '1', '2', '3' ]]
    dataary.forEach(function(element) {
    console.log(element.length);
    });

I would do it that way...

dataary.reduce((count, innerArray) => count + innerArray.length, 0);