How to initialize array variable

Question

I want to dynamically initialize a variable array in javascript. I keep getting unexpected token illegal token errors.

in my current script, serviceLimit = 10; but it could be changed at any time.

Attempt #1

var jqSvcPhrase = {};
for(i=1; i<=serviceLimit; i++) {
  jqSvcPhrase[+ i +] = ''; // produces - Uncaught SyntaxError: Unexpected token ]
}

Attempt #2

var jqSvcPhrase = {};
for(i=1; i<=serviceLimit; i++) {
  jqSvcPhrase\[+ i +\] = ''; // produces - Uncaught SyntaxError: Unexpected token ILLEGAL
}

Attempt #3

var jqSvcPhrase = {};
for(i=1; i<=serviceLimit; i++) {
  jqSvcPhrase\\[+ i +\\] = ''; // produces - Uncaught SyntaxError: Unexpected token ILLEGAL
}

You're not trying to do that in jQuery. You're trying to do that in Javascript... — i-CONICA
– i-CONICA, Commented Jan 5, 2015 at 15:36

Rory McCrossan · Accepted Answer · 2015-01-05 15:34:50Z

1

i is an integer type, so does not require concatenation. Try this:

var jqSvcPhrase = {};
for (i = 1; i <= serviceLimit; i++) {
      jqSvcPhrase[i] = '';
}

answered Jan 5, 2015 at 15:34

Rory McCrossan

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Comments

tckmn · Accepted Answer · 2015-01-05 15:34:47Z

1

Uhh... what's with all the +s?

var jqSvcPhrase = {};
for(i=1; i<=serviceLimit; i++) {
  jqSvcPhrase[i] = '';
}

answered Jan 5, 2015 at 15:34

tckmn

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3 Comments

H. Ferrence Over a year ago

Was simply copying and pasting prior code that worked.

a-d Over a year ago

@H.Ferrence Does this means the code was eval'd somewhere? I feel sorry for your code D:

H. Ferrence Over a year ago

No use of eval but thanks for your sympathies & concerns @aduch :)

Fuzzyma · Accepted Answer · 2015-01-05 15:36:17Z

1

First of all you are declaring an object and not an array. It should be var jqSvcPhrase = []; instead. Furthermore the + is not needed. It has to be jqSvcPhrase[i]

answered Jan 5, 2015 at 15:36

Fuzzyma

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2 Comments

Rory McCrossan Over a year ago

Objects can still be accessed by index.

Fuzzyma Over a year ago

"I want to dynamically initialize a variable array [... ]" - you won't he able to use array functions when you got an object. If may be possible but better be careful here

Jordan · Accepted Answer · 2015-01-05 15:39:06Z

0

Why use curly brackets? Use square brackets for arrays.

var jqSvcPhrase = [];
for(i=1; i<=serviceLimit; i++) {
      jqSvcPhrase[i] = '';
}

answered Jan 5, 2015 at 15:39

Jordan

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Comments

Margus · Accepted Answer · 2015-01-05 15:50:15Z

0

Array syntax (Manual ):

[element0, element1, ..., elementN] 
new Array(element0, element1[, ...[, elementN]]) 
new Array(arrayLength)

This should be :

var jqSvcPhrase = new Array(serviceLimit);

and it would make sense to initialize values:

for (x in jqSvcPhrase) { x = ''; }

answered Jan 5, 2015 at 15:50

Margus

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