Using the loop value inside an Array

Question

I want loop through 1 to 21 and then use this loop numbers for getting an Array of Strings ['e1.wkh',...'e21.wkh']. But right now the only value I got is ['e21.wkh'].

function calculateStats() {
 var obj = {}
 var deviceId = "34534";
 for (var i = 1; i <= 21; i++) {
 var loo = i.toString();
 console.log(loo);
 obj[deviceId] = ['e' + loo + '.kwh'];
 console.log(obj[deviceId]);
 }
}

• Markai: The reason is that you are always using deviceId as the element name here: obj[deviceId] = ['e' + loo + '.kwh']; So you always overwrite the last value of obj[deviceId] How should the elements be named instead?
• Vishnu: index of your obj remain's same for for whole loop that is your problem in statement obj[deviceId] = ['e' + loo + '.kwh']; you have to Change this and make index incremental to store all the values generated by your loop

Answer 1

Replace below line

obj[deviceId] = ['e' + loo + '.kwh'];

With

(obj[deviceId])?obj[deviceId].push('e' + loo + '.kwh'):obj[deviceId]=['e' + loo + '.kwh'];

Answer 2

Here is a possible solution:

The issue was you were overwriting your obj[deviceId].

function calculateStats() {
 var obj = {}
 var deviceId = "357803045265259@rayleigh";
 obj[deviceId] = [];
 for (var i = 1; i <= 21; i++) {
 var loo = i.toString();
 console.log(loo);
 obj[deviceId].push('e' + loo + '.kwh');
 console.log(obj[deviceId]);
 }
}

https://jsfiddle.net/q651uhde/

• RegarBoy: obj[deviceId] should be equal to the array of 'e' + loo + '.kwh'
• Arathi Sreekumar: I have updated with a jsfiddle. It is an array of 'e' + loo + '.kwh'.
• RegarBoy: I have got such an error: Uncaught TypeError: Cannot read property 'push' of undefined
• Arathi Sreekumar: Did you add this line before the for loop: obj[deviceId] = []; ?
• RegarBoy: Alright it is working and both the ternary operation : (obj[deviceId])?obj[deviceId].push('e' + loo + '.kwh'):obj[deviceId]=['e' + loo + '.kwh']

Answer 3

function calculateStats() {

var obj = [];

var deviceId = "1111@rayleigh";
for (var i = 1; i <= 21; i++) {
 var loo = i.toString();
 console.log(loo);
 obj.push('e' + loo + '.kwh');
}

console.log(obj);

} obj carries your array, is that what you want?

Answer 4

Set up the array first and then push each string to it. No need to convert the index to a string as it will be coerced to a string when you push it to the array anyway.

function calculateStats() {
 var obj = {};
 var deviceId = "357803045265259@rayleigh";
 obj[deviceId] = [];
 for (var i = 1; i <= 21; i++) {
 obj[deviceId].push('e' + i + '.kwh');
 }
}

DEMO