TypeScript is a good advancement in the javascript ecosystem.
Today we are going to talk about the difference between the String
and string
types in Typescript.
Type error: Type 'String' is not assignable to type 'string'.
Let's take a look at the above error.
To begin, we know that whether we use String or string, we would want to refer to the same thing. But both of those are a little different.
String is a class in JavaScript to construct strings. It provides a way of creating strings using that constructor. What we get using String is an object.
If you check if it's a string or not, you will get *
object
.
let name = new String('Mike');
console.log(typeof name); // object
string on the other hand does not exist in JavaScript. Rather it is used in Typescript to tell it it is an actual string.
Therefore, when you are creating a function, type or interface in Typescript, it is recommended to use lowercase string
to tell Typescript you want to get an actual string. If you use String
, then you will get an object (which is not what you would want).
Thank you for reading.
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