객체 생성자 함수_프로토타입(prototype)

• java의 static 개념과 같음
• 메소드를 공유
• 메모리 효율성을 위함

 

<객체 생성자 함수>

    <script>
    
		function CheckWeight(name, height, weight){
            this.name=name;
            this.height=height;
            this.weight=weight;
            this.minWeight;
            this.maxWeight; 

            this.getInfo = function(){
            var str="";
            str += "이름 : " + this.name + ", ";
            str += "키 : " + this.height + ", ";
            str += "몸무게 : " + this.weight;
            return str;
        }

            this.getResult = function(){
            this.minWeight=(this.height - 100) * 0.9 -5;
            this.maxWeight=(this.weight -100) * 0.9 +5;
        
            if(this.weight >= this.minWeight  && this.weight <= this.maxWeight){
                return "정상몸무게 입니다.";
            }else if (this.weight < this.minWeight){
                return "몸무게 미달입니다."
            }else{
                return "몸무게 초과입니다."
            }
        }
      }

        var limi = new CheckWeight("리미", 168, 59);
        var bini = new CheckWeight("비니", 181, 80);
        
        console.log(limi);
        console.log(bini);

        
    </script>

 

 

<prototype>

• 메소드를 생성자 함수 밖으로 빼낸다
• this가 아닌 객체 생성자명.prototype.함수명을 사용

 

    <script>
        function CheckWeight(name, height, weight){
            this.name=name;
            this.height=height;
            this.weight=weight;
            this.minWeight;
            this.maxWeight; 
    }

            CheckWeight.prototype.getInfo = function(){
            var str="";
            str += "이름 : " + this.name + ", ";
            str += "키 : " + this.height + ", ";
            str += "몸무게 : " + this.weight;
            return str;
        }

            CheckWeight.prototype.getResult = function(){
            this.minWeight=(this.height - 100) * 0.9 -5;
            this.maxWeight=(this.weight -100) * 0.9 +5;
        
            if(this.weight >= this.minWeight  && this.weight <= this.maxWeight){
                return "정상몸무게 입니다.";
            }else if (this.weight < this.minWeight){
                return "몸무게 미달입니다."
            }else{
                return "몸무게 초과입니다."
            }
        }
        
       	var limi = new CheckWeight("리미", 168, 59);
        var bini = new CheckWeight("비니", 181, 80);
        
        console.log(limi);
        console.log(bini);
        
        console.log(limi.getInfo(), limi.getResult());
        console.log(bini.getInfo(), bini.getResult());
 </script>