TypeScript Functions Functions with Union Types
Example
A TypeScript function can take in parameters of multiple, predefined types using union types.
function whatTime(hour:number|string, minute:number|string):string{
return hour+':'+minute;
}
whatTime(1,30) //'1:30'
whatTime('1',30) //'1:30'
whatTime(1,'30') //'1:30'
whatTime('1','30') //'1:30'
Typescript treats these parameters as a single type that is a union of the other types, so your function must be able to handle parameters of any type that is in the union.
function addTen(start:number|string):number{
if(typeof number === 'string'){
return parseInt(number)+10;
}else{
else return number+10;
}
}
