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: }
Tag Archives: 99java
2: Loops
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 |
1: How to Answer These Questions
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:
Tony Ballantyne Tech 