In Javascript, how to convert a string to a property name?

Question

I have a global object with various properties whose values are strings. When a user types a string into an HTML input, I'm using javascript to assign that string to a variable. I need to convert that string to a property name and return the string associated with that property.

For example:

myglobalobject = {

    propertyname : "String value to be returned."

}

function GetInput(){
    mystring = document.getElementById('input').value;

    myproperty = convertstringToProperty(str); //This is where I need a solution

    return myglobalobject.myproperty;
}

Directly use `myglobalobject[mystring]`. You dont need to convert anything. — Prakash Sharma, Mar 11 '18 at 18:53

score 3 · Answer 1 · answered Mar 11 '18 at 18:55

3

Well, properties can be accessed with, you guess it, a string:

const myObject = {
  property1: 0,
  property2: 1,
};

const inputFromUser = 'property1';
console.log(myObject[inputFromUser]);

answered Mar 11 '18 at 18:55

Rakha Kanz Kautsar

79
3

score 3 · Accepted Answer · answered Mar 11 '18 at 18:55

Just use a computed property:

return myglobalobject[mystring];

This is a generalization of the fact that property accesses using dot notation are the same as accessing with brackets and a string literal:

obj.prop === obj["prop"];

So when you have something that isn't a string literal, just use the bracket notation.

score 0 · Answer 3 · answered Mar 11 '18 at 18:56

You don't even need a function:

var myglobalobject = {
    propertyname : "String value to be returned."
}
function GetInput(){
    mystring = 'anotherKey';

    return myglobalobject[mystring] = undefined;
}
GetInput()
console.log(myglobalobject)

In Javascript, how to convert a string to a property name?

3 Answers3