Javascript: Unable to create JSON object using String.fromCharCode for generating keys and values

Question

I am trying to fix character mappings on paste within a text area element using the following object to match characters.

var replacementMap = {
    String.fromCharCode(61607) : String.fromCharCode("9632"),  //solid box
    String.fromCharCode(61623) : String.fromCharCode("9679"),  //solid circle
    String.fromCharCode(61656) : String.fromCharCode("9654"),  //right arrow
    String.fromCharCode(61692) : String.fromCharCode("10003"), //checkmark
    String.fromCharCode(61558) : String.fromCharCode("10070")  //black diamond minus white X
};

This object is called from a regular expression to change the characters within a string based on the character codes but currently firebug is throwing the following error:

SyntaxError: missing : after property id
String.fromCharCode(61607) : String.fromCharCode("9632"),  //solid

That’s not an Array, that’s an object … http://stackoverflow.com/a/19837961/1427878 — CBroe, Aug 04 '14 at 16:05

score 2 · Answer 1 · answered Aug 04 '14 at 16:08

You can't use function/method calls as object literal keys. You'll want something like:

var replacementMap = {};

replacementMap[ String.fromCharCode(61607) ] = String.fromCharCode("9632");  //solid box
replacementMap[ String.fromCharCode(61623) ] = String.fromCharCode("9679");

// etc.

score 2 · Accepted Answer · answered Aug 04 '14 at 16:11

If you just want the object to compile, you could do like this instead:

var replacementMap = {};

replacementMap[String.fromCharCode(61607)] = String.fromCharCode("9632");  //solid box
replacementMap[String.fromCharCode(61623)] = String.fromCharCode("9679");  //solid circle
replacementMap[String.fromCharCode(61656)] = String.fromCharCode("9654");  //right arrow
replacementMap[String.fromCharCode(61692)] = String.fromCharCode("10003"); //checkmark
replacementMap[String.fromCharCode(61558)] = String.fromCharCode("10070");  //black diamond minus white X

But they are right - it's not an array! :)

Paul Roub was there first though (just for the record) – hasse Aug 04 '14 at 16:26 — hasse, Aug 04 '14 at 16:26

Javascript: Unable to create JSON object using String.fromCharCode for generating keys and values

2 Answers2