[typescript] Enum 열거형 타입

숫자 혹은 문자열 값 집합에 이름을 부여할 수 있는 타입

값의 종류가 일정한 범위로 정해져 있는 경우 유용함.

구문 )

enum name {
	값1,  =======>0번째
	값2,  =======>1번째
	값3   =======>2번째
}

 

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실습

enum Week {
    Sun,
    Man,
    Tue=7,  // Tue=7 값을주면 7 8 9 10 순으로 지정됨
    Wed,
    Thu,
    Fri,
    Sat
}
enum Color {
    Red = "red",
    Green = "green",
    Blue = "blue"
}

console.log(Week.Man); //1
console.log(Week.Sat); //11
console.log(Week.Wed); //8
console.log(Week[0]); //Sun
console.log(Week[1]); //Man
console.log(Color.Red); //red
console.log(Color["Green"]); //green

let aaa:Color = Color.Blue; // 정해진 값 사용해야함

console.log(aaa)  //blue

 

조건문(switch) 사용

enum StarbucksGrade {
    WELCOME,
    GREEN,
    GOLD
}

function getDicound(v: StarbucksGrade) : number {
    switch(v){
        case StarbucksGrade.WELCOME:
            return 0;
        case StarbucksGrade.GREEN:
            return 5;
        case StarbucksGrade.GOLD:
            return 10;        
    }
}
console.log(getDicound(StarbucksGrade.WELCOME))   //0