CODEWITHSUNDEEP
javascriptnode.js
Ivan Peshev
Ivan Peshev

Reputation: 455

How to declare and use map/dictionary in Node.js?

is it possible something like this is node.js ?

var LANGUAGE = {
    LANG1: 'Language 1',
    LANG2 'Language 2'
}

var TARGET = {
    TARG1: { LANG1: 'target 1 in lang 1', LANG2: 'target 1 in lang 2' },
    TARG2: { LANG1: 'target 2 in lang 1', LANG2: 'target 2 in lang 2' }
}

var ACTION = {
    ACT1: { LANG1: 'action 1 in lang 1', LANG2: 'action 1 in lang 2' },
    ACT2: { LANG1: 'action 2 in lang 1', LANG2: 'action 2 in lang 2' }  
}


var currentLanguage = LANGUAGE.LANG1;
var currentTarget = TARGET.TARG2;
var currentAction = ACTION.ACT1;

var message = 'You have successfully performed ' + currentAction[currentLanguage] + ' on ' + currentTarget[currentLanguage];

console.log(message);

I'm not sure that in the source above there is any relation between LANGUAGE.LANG1 and TARG1: { LANG1: etc...

======== updated with the result after running this in VSCode =======

You have successfully performed undefined on undefined

Upvotes: 0

Views: 4999

Answers (3)

Ivan Peshev
Ivan Peshev

Reputation: 455

Thanks to 31piy,

I've found a way it works. Maybe it's not the best one.

var LANGUAGE = {
    LANG1: 'Language 1',
    LANG2: 'Language 2'
}

var TARGET = {
    TARG1: new Map(),
    TARG2: new Map() 
}

var ACTION = {
    ACT1: new Map(),
    ACT2: new Map() 
}

TARGET.TARG1.set(LANGUAGE.LANG1, 'target 1 in lang 1');
TARGET.TARG1.set(LANGUAGE.LANG2, 'target 1 in lang 2');
TARGET.TARG2.set(LANGUAGE.LANG1, 'target 2 in lang 1');
TARGET.TARG2.set(LANGUAGE.LANG2, 'target 2 in lang 2');

ACTION.ACT1.set(LANGUAGE.LANG1, 'action 1 in lang 1');
ACTION.ACT1.set(LANGUAGE.LANG2, 'action 1 in lang 2');
ACTION.ACT2.set(LANGUAGE.LANG1, 'action 2 in lang 1');
ACTION.ACT2.set(LANGUAGE.LANG2, 'action 2 in lang 2');

var currentLanguage = LANGUAGE.LANG1;
var currentTarget = TARGET.TARG2;
var currentAction = ACTION.ACT1;

var message = 'You have successfully performed ' + currentAction.get(currentLanguage) + ' on ' + currentTarget.get(currentLanguage);

console.log(message);

And the result is as expected :)

You have successfully performed action 1 in lang 1 on target 2 in lang 1

Upvotes: 0

Martin Stone
Martin Stone

Reputation: 13007

Absolutely, yes. Your problem is that the values in your LANGUAGE object need to be the keys in the other objects, so...

var LANGUAGE = {
    LANG1: 'LANG1',
    LANG2: 'LANG1'
}

(You're also missing the second colon in the code you posted.)

Using the above prints...

You have successfully performed action 1 in lang 1 on target 2 in lang 1

Upvotes: 2

hope_is_grim
hope_is_grim

Reputation: 1934

You should read more about javascript dot and bracket notation.
In your case currentAction[currentLanguage] will be currentAction['Language 1'] and there is no value with key 'Language 1' in the currentAction object (which equals to { LANG1: 'action 1 in lang 1', LANG2: 'action 1 in lang 2' })
currentAction['LANG1'] or currentAction.LANG1 will return the value you want.

ES6 has the dynamic key syntax, where you can use a variable for the key in object literal
{ [LANGUAGE.LANG1]: 'some value'}

Upvotes: 2

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