for循环while循环do、while循环打印1234

public class While{
    public static void main(String[] args){
        //for打印1-4
        
        for(int a =1;a<5;a++ ){
            System.out.println(a);
        }
        //while打印1-4
        int b=1;
        
        while(b<5){
            System.out.println(b);
            b++;
        }
        
        int d =1;
        while(true){
            System.out.println(d);
            d++;
            if(d==5){
                break;
            }
        }
        //do...while
        int c =1;
        do{
            System.out.println(c);
            c++;
        }while(c<5);
        
    }
}