How to use Object.values with typescript?
I am trying to form a comma separated string from an object,
const data = {"Ticket-1.pdf":"8e6e8255-a6e9-4626-9606-4cd255055f71.pdf","Ticket-2.pdf":"106c3613-d976-4331-ab0c-d581576e7ca1.pdf"};
const values = Object.values(data).map(x => x.substr(0, x.length - 4));
const commaJoinedValues = values.join(',');
console.log(commaJoinedValues);
How to do this with TypeScript?
getting an error file:
severity: 'Error'
message: 'Property 'values' does not exist on type 'ObjectConstructor'.'
at: '216,27'
source: 'ts'
Solution 1:
Object.values()
is part of ES2017, and the compile error you are getting is because you need to configure TS to use the ES2017 library. You are probably using ES6 or ES5 library in your current TS configuration.
Solution: use es2017
or es2017.object
in your --lib
compiler option.
For example, using tsconfig.json
:
"compilerOptions": {
"lib": ["es2017", "dom"]
}
Note that targeting ES2017 with TypeScript does not emit polyfills in the browser for ES2017 (meaning the above solves your compile error, but you can still encounter a runtime error because the browser doesn't implement ES2017 Object.values
), it's up to you to polyfill your project code yourself if you want. And since Object.values
is not yet well supported by all browsers (at the time of this writing) you definitely want a polyfill: core-js
will do the job.
Solution 2:
using Object.keys instead.
const data = {
a: "first",
b: "second",
};
const values = Object.keys(data).map(key => data[key]);
const commaJoinedValues = values.join(",");
console.log(commaJoinedValues);
Solution 3:
You can use Object.values
in TypeScript by doing this (<any>Object).values(data)
if for some reason you can't update to ES7 in tsconfig.
Solution 4:
Instead of
Object.values(myObject);
use
Object["values"](myObject);
In your example case:
const values = Object["values"](data).map(x => x.substr(0, x.length - 4));
This will hide the ts compiler error.