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javascriptpropertiesobject-literal

create object using variables for property name

Is it at all possible to use variable names in object literal properties for object creation?

Example

function createJSON (propertyName){
    return { propertyName : "Value"};
}

var myObject = createJSON("myProperty");

console.log(myObject.propertyName);  // Prints "value"
console.log(myObject.myProperty);  // This property does not exist
Solution

  • If you want to use a variable for a property name, you can use Computed Property Names. Place the variable name between square brackets:

    var foo = "bar";
var ob  = { [foo]: "something" }; // ob.bar === "something"

    If you want Internet Explorer support you will need to use the ES5 approach (which you could get by writing modern syntax (as above) and then applying Babel):

    Create the object first, and then add the property using square bracket notation.

    var foo = "bar";
var ob  = {};
ob[foo] = "something"; // === ob.bar = "something"

    If you wanted to programatically create JSON, you would have to serialize the object to a string conforming to the JSON format. e.g. with the JSON.stringify method.