declare function type typescript code example
Example 1: types function typescript
interface Safer_Easy_Fix {
title: string;
callback: () => void;
}
interface Alternate_Syntax_4_Safer_Easy_Fix {
title: string;
callback(): void;
}
Example 2: typescript function
function greet(name: string): string {
return name.toUpperCase();
}
console.log(greet("hello"));
console.log(greet(1));
Example 3: typescript pass a function as an argunetn
class Foo {
save(callback: (n: number) => any) : void {
callback(42);
}
}
var foo = new Foo();
var strCallback = (result: string) : void => {
alert(result);
}
var numCallback = (result: number) : void => {
alert(result.toString());
}
foo.save(strCallback);
foo.save(numCallback);
Example 4: typescript default parameter
function sayName({ first, last = 'Smith' }: {first: string; last?: string }): void {
const name = first + ' ' + last;
console.log(name);
}
sayName({ first: 'Bob' });
Example 5: typescript function type
interface Date {
toString(): string;
setTime(time: number): number;
}
Example 6: types function typescript
interface Easy_Fix_Solution {
title: string;
callback: Function;
}