I sometimes feel I am forced to use let
instead of const
in TypeScript even I want to use const
to prevent reassignments.
When we use if
or switch
, there are cases that seems we need to use let
. However, we do not have to use let
actually.
const fruitNum: number = 0 // a number to represent a type of fruit
let fruitName: string = "Unknown"
switch(fruitNum) {
case 0:
fruitName = "Apple"
break
case 1:
fruitName = "Banana"
break
default:
break
}
Instead of the above code, we may want to use a anonymous function to make fruitName
a const
.
const fruitNum: number = 0 // a number to represent a type of fruit
const fruitName: string = (() => {
switch(fruitNum) {
case 0:
return "Apple"
case 1:
return "Banana"
default:
return "Unknown"
}
})()
Hope this makes your code more cleaner!