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2023.DEC.08(FRI) JAVA DAY5_별 숫자 늘리고 줄여서 다이아몬드 모양

✅ Daily Report

📌 TO-DO LIST

  • submit github blog post
  • study yalco method, scanner
  • lesson 17, 18, 19, 20, 21, 22
  • assigment: make stars into diamond array using for

✅ Today I Learned

✔️ using for in for to increase and decrease the number of stars

⭐️ 별 1~5까지 순서대로 내려가기

💡 while 문으로 작성하면?

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        int line =0;

        while (line < 5){
            int star= 0;
            while(star <= line){
                System.out.print("*");
                star++;
            }
            System.out.println();
            line++;
        }

💡 for문으로 작성하면?

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       int max= 5;
        for(int line=0; line < max; line++){
           for (int star=0; star <= line; star++){
               System.out.print("*");
           }
           System.out.println();
       }

⭐️ 별 5~1로 거꾸로 내려가기

💡 while 문으로 작성하면?

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    int line =0;

       while (line > 0) {
           int star = line--;
           while (star-- > 0) {
               System.out.print("*");
           }
           System.out.println();
   }

// *****
// ****
// ***
// **
// *

💡 for문으로 작성하면?

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for (int i = line; i > 0; i--) {
            for (int j = i; j > 0; j--) {
                System.out.print("@");
            }
            System.out.println();
        }

⭐️ 별 커졌다가 작아지기

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int size= 10;
    for (int line= 0; line <  size; line++){
        for (int star=0; star <= line; star++){
            if(star%2 ==0) continue;
            System.out.print("*");
        }
        if(line%2 ==0) continue;
        System.out.println();
    }
    for (int line= size; 0 <  line; line--){
        for (int star=0; star <= line-3; star++){
            if(star%2 ==0) continue;
            System.out.print("*");
        }
        if(line%2 ==0) continue;
        System.out.println();
    }

// *
// ***
// *****
// *******
// *********
// *******
// *****
// ***
// *

⭐️ 별 다이아 모양으로 출력

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        int size=3;
        for(int line=1; line <= size; line++){
            for(int space= size-line; space >=1; space-- ){
                System.out.print(" ");
            }
            for(int star= 1; star <= 2*line -1; star++){
                System.out.print("*");
            }
            System.out.println();
        }
        for(int line= size-1; line>=1; line-- ){
            for(int space= 1; space<= size-line; space++){
                System.out.print(" ");
            }
            for(int star=1; star<=2*line-1; star++){
                System.out.print("*");
            }System.out.println();
        }

//   *
//  ***
// *****
//  ***
//   *

how to get input from user using scanner

how do declare and use methods in JAVA.

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