Expanding on the Number class:
interface Number {
evolution(now: number, before: number): string;
}
Number.prototype.magnitude = function(d=1, suffix="") {
//…
}
I enjoy incorporating default parameters.
However, encountering an issue when leaving out explicit parameters:
label = "÷ " + show.magnitude();
An error occurred stating "The supplied parameters do not match signature"
To inform the TypeScript compiler that certain parameters are optional, you can use the "?" symbol at the end of these parameters:
In JavaScript, all parameters are considered optional, allowing users to omit them if they choose. In such cases, the value defaults to undefined. To replicate this behavior in TypeScript, simply append a "?" to the parameters you wish to be optional.
Below is an example demonstrating how to achieve what you're looking for:
interface ISum {
(baz?: number, buz?: number): number;
}
let sum: ISum = (baz = 1, buz = 2) => {
return baz + buz;
}
console.log(sum()); //Output: 3
console.log(sum(2)); //Output: 4
console.log(sum(2, 7)); //Output: 9
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