How to fill a Javascript object literal with many static key value pairs efficiently

Question

The typical way of creating a Javascript object is the following   var map   new Object    map myKey1    myObj1  map myKey2    myObj2    I need to create such a map where both keys and values are Strings  I have a large but static set of pairs to add to the map   Is there any way to perform something like this in Javascript   var map         aaa    rrr        bbb    ppp             or do I have to perform something like this for each entry   map  aaa    rrr   map  bbb    ppp         Basically  remaining Javascript code will loop over this map and extract values according to criterias known  at runtime   If there is a better data structure for this looping job  I am interested too  My objective is to minimize code

User · Answer

It works fine with the object literal notation:

var map = { key : { "aaa", "rrr" }, 
            key2: { "bbb", "ppp" } // trailing comma leads to syntax error in IE!
          }

Btw, the common way to instantiate arrays

var array = [];
// directly with values:
var array = [ "val1", "val2", 3 /*numbers may be unquoted*/, 5, "val5" ];

and objects

var object = {};

Also you can do either:

obj.property     // this is prefered but you can also do
obj["property"]  // this is the way to go when you have the keyname stored in a var

var key = "property";
obj[key] // is the same like obj.property

User · Answer

In ES2015 a k a ES6 version of JavaScript  a new datatype called Map is introduced    let map   new Map    key1    value1      key2    value2      map get  key1         gt  value1   check this reference for more info

User · Answer

JavaScript s object literal syntax  which is typically used to instantiate objects  seriously  no one uses new Object or new Array   is as follows   var obj          key    value        another key    another value        anUnquotedKey   more value        For arrays it s   var arr          value        another value        even more values       If you need objects within objects  that s fine too   var obj          subObject              key    value              another object               some key    some value             another key    another value             an array      this    is    ok    as    well              This convenient method of being able to instantiate static data is what led to the JSON data format   JSON is a little more picky  keys must be enclosed in double-quotes  as well as string values     foo   bar    keyWithIntegerValue  123

User · Answer

Give this a try   var map     aaa    rrr    bbb    ppp

User · Answer

The syntax you wrote as first is not valid  You can achieve something using the follow   var map      aaa    rrr    bbb    ppp     etc

[javascript] How to fill a Javascript object literal with many static key/value pairs efficiently?

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