## – Loop Solutions

```1:  package nnloops;
2:
3:  import java.util.Scanner;
4:
5:  public class NNLoops {
6:
7:      NNLoops()
8:      {
9:          //oneToTen();
10:          //oddNumbers();
11:          //squareNumbers();
12:          //random4();
13:          //even(20);
14:          //powers(8);
15:          //areWeThereYet();
16:          //triangle();
17:          //tableSquare();
18:          tableSquares(6);
19:
20:      }
21:
22:      void oneToTen()
23:      {
24:          for(int i=1; i <11; i++)
25:          {
26:              System.out.println(i);
27:          }
28:      }
29:
30:      void oddNumbers()
31:      {
32:          for (int i=1; i<20; i+=2)
33:          {
34:              System.out.println(i);
35:          }
36:      }
37:
38:      void squareNumbers()
39:      {
40:          for (int i=1; i<11; i++)
41:          {
42:              System.out.println(i*i);
43:          }
44:      }
45:
46:      void random4()
47:      {
48:          for (int i=0; i<4; i++)
49:          {
50:              System.out.println((int)(Math.random()*10)+1);
51:          }
52:      }
53:
54:      void even(int n)
55:      {
56:          for (int i=1; i<n; i+=2)
57:          {
58:              System.out.println(i);
59:          }
60:      }
61:
62:      void powers (int n)
63:      {
64:          for (int i =1; i<=n; i++)
65:          {
66:              System.out.println(Math.pow(2, i));
67:          }
68:      }
69:
70:      void areWeThereYet()
71:      {
72:          Scanner scan = new Scanner(System.in);
73:          do
74:          {
75:              System.out.println("Are we there yet?");
76:          } while(!scan.nextLine().equals("Yes"));
77:          System.out.println("Good!");
78:      }
79:
80:      void triangle()
81:      {
82:          for(int i = 0; i<6; i++)
83:          {
84:              for (int j= 0; j<i; j++)
85:              {
86:                  System.out.print("*");
87:              }
88:              System.out.println("");
89:          }
90:      }
91:
92:      void tableSquare()
93:      {
94:          for(int i = 1; i<=4; i++)
95:          {
96:              for (int j=1; j<=4; j++)
97:              {
98:                  System.out.print("|"+ i*j +"\t");
99:              }
100:              System.out.println("|");
101:
102:          }
103:      }
104:
105:      void tableSquares(int n)
106:      {
107:          for(int i = 1; i<=n; i++)
108:          {
109:              for (int j=1; j<=n; j++)
110:              {
111:                  System.out.print("|"+ i*j +"\t");
112:              }
113:              System.out.println("|");
114:
115:          }
116:      }
117:
118:
119:      public static void main(String[] args) {
120:         new NNLoops();
121:      }
122:  }```

## 2.1 1 to 10

Write a method that prints the numbers 1 to 10

#### 2.1.1 Example

``` 1:  oneToTen()
2:   *** Output ***
3:  1
4:  2
5:  3
6:  4
7:  5
8:  6
9:  7
10:  8
11:  9
12:  10```

### 2.2 Odd Numbers

Write a method that prints the positive odd numbers less than 20

#### 2.2.1 Example

``` 1:  oddNumbers()
2:   *** Output ***
3:  1
4:  3
5:  5
6:  7
7:  9
8:  11
9:  13
10:  15
11:  17
12:  19```

### 2.3 Square Numbers

Write a method that prints the square numbers up to 100

#### 2.3.1 Example

``` 1:  squares()
2:   *** Output ***
3:  1
4:  4
5:  9
6:  16
7:  25
8:  36
9:  49
10:  64
11:  81
12:  100```

### 2.4 Random Numbers

Write a for loop to print out four random integers between 1 and 10

#### 2.4.1 Example

```1:  random4()
2:   *** Output ***
3:  3
4:  5
5:  2
6:  8```

### 2.5 Even Numbers < n

Write a method to print out the positive even numbers less than n

#### 2.5.1 Example

``` 1:  even(20)
2:   *** Output ***
3:  2
4:  4
5:  6
6:  8
7:  10
8:  12
9:  14
10:  16
11:  18```

### 2.6 Powers of 2

Write a method to print out the powers of 2 from 21 up to 2n

#### 2.6.1 Example

``` 1:  powers(8)
2:   *** Output ***
3:  2
4:  4
5:  8
6:  16
7:  32
8:  64
9:  128
10:  256```

### 2.7 Are we there yet?

Write a program that outputs “Are we there yet?” and then waits for input. If the input is “Yes” the program outputs “Good!” and exits, otherwise the program loops.

#### 2.7.1 Example

```1:  "Are we there yet?"
2:  No
3:  "Are we there yet?"
4:  Spoons
5:  "Are we there yet?"
6:  Yes
7:  Good!```

### 2.8 Triangle

Write a method that uses nested loops to produce the following pattern

```1:  triangle()
2:   *** Output ***
3:  *
4:  **
5:  ***
6:  ****
7:  *****```

### 2.9 Table Square

Write a method that prints out a 4 x 4 table square

#### 2.9.1 Example

```1:  tableSquare()
2:   *** Output ***
3:  A 4 x 4 table square
4:  | 1 | 2 |  3 |  4 |
5:  | 1 | 2 |  3 |  4 |
6:  | 2 | 4 |  6 |  8 |
7:  | 3 | 6 |  9 | 12 |
8:  | 4 | 8 | 12 | 16 |```

### 2.10 Table Squares

Extend your answer to the last question produce a method that will print out a n x n table square

#### 2.10.1 Example

``` 1:  tableSquares(6)
2:   *** Output ***
3:  A 6 x 6 table square
4:  | 1 |  2 |  3 |  4 |  5 |  6 |
5:  | 2 |  4 |  6 |  8 | 10 | 12 |
6:  | 3 |  6 |  9 | 12 | 15 | 18 |
7:  | 4 |  8 | 12 | 16 | 20 | 24 |
8:  | 5 | 10 | 15 | 20 | 25 | 30 |
9:  | 6 | 12 | 18 | 24 | 30 | 36 |```

## Write methods to solve all of the questions. Here are two example questions and their solutions. Notice that the first method prints a value, the second method returns a value.

### 1.1 Hello <Name>

Write a method that accepts a name as a parameter and prints out “Hello ” <name>

#### 1.1.1 Example

```1:  hello("Kim")
2:   *** Output ***
3:  Hello Kim```

### 1.2 Average of two numbers

Write a method that accepts two numbers and returns the average of the two numbers.

#### 1.2.1 Example

```1:  System.out.println(average(3,4));
2:   *** Output ***
3:  3.5```

### 1.3 Solutions

``` 1:  public class NinetyNine {
2:
3:      NinetyNine()
4:      {
5:          hello("Kim");
6:          System.out.println(average(3,4));
7:      }
8:
9:      void hello(String s)
10:      {
11:          System.out.println("Hello " + s);
12:      }
13:
14:      double average(double x, double y)
15:      {
16:          return (x+y)/2;
17:      }
18:
19:      public static void main(String[] args)
20:      {
21:          new NinetyNine();
22:      }
23:  }
24:```