Course
Introduction
Print an Integer (Entered by the User)Add Two IntegersMultiply two Floating Point NumbersFind ASCII value of a characterCompute Quotient and RemainderSwap Two NumbersCheck Whether a Number is Even or OddFind the Frequency of Character in a StringRemove All Whitespaces from a StringRound a Number to n Decimal PlacesDecision Making and Loop
Check Whether an Alphabet is Vowel or ConsonantFind the Largest Among Three NumbersFind all Roots of a Quadratic EquationCheck Leap YearCheck Whether a Number is Positive or NegativeCheck Whether a Character is Alphabet or NotCalculate the Sum of Natural NumbersFind Factorial of a NumberGenerate Multiplication TableDisplay Fibonacci SeriesFind GCD of two NumbersFind LCM of two NumbersDisplay Characters from A to Z using loopCount Number of Digits in an IntegerReverse a NumberCalculate the Power of a NumberCheck Whether a Number is Palindrome or NotCheck Whether a Number is Prime or NotDisplay Prime Numbers Between Two IntervalsCheck Armstrong NumberDisplay Armstrong Number Between Two IntervalsDisplay Factors of a NumberMake a Simple Calculator Using switch...caseCount the Number of Vowels and Consonants in a SentenceSort Elements in Lexicographical Order (Dictionary Order)Create Pyramid and PatternFunctions
Display Prime Numbers Between Intervals Using FunctionDisplay Armstrong Numbers Between Intervals Using FunctionCheck Whether a Number can be Expressed as Sum of Two Prime NumbersFind the Sum of Natural Numbers using RecursionFind Factorial of a Number Using RecursionFind G.C.D Using RecursionConvert Binary Number to Decimal and vice-versaConvert Octal Number to Decimal and vice-versaConvert Binary Number to Octal and vice-versaReverse a Sentence Using Recursioncalculate the power using recursionArrays
Calculate Average Using ArraysFind Largest Element in an ArrayCalculate Standard DeviationAdd Two Matrix Using Multi-dimensional ArraysMultiply to Matrix Using Multi-dimensional ArraysMultiply two Matrices by Passing Matrix to a FunctionFind Transpose of a MatrixPrint an ArrayConcatenate Two ArraysConvert Character to String and Vice-VersaCheck if An Array Contains a Given ValueCollections
Join Two ListsConvert List (ArrayList) to Array and Vice-VersaConvert Map (HashMap) to ListConvert Array to Set (HashSet) and Vice-VersaSort a Map By ValuesObject and Class
Add Two Complex Numbers by Passing Class to a FunctionCalculate Difference Between Two Time PeriodsAdvanced
Convert String to DateGet Current Date/TImeConvert Milliseconds to Minutes and SecondsAdd Two DatesGet Current Working DirectoryConvert Byte Array to HexadecimalCreate String from Contents of a FileAppend Text to an Existing FileConvert a Stack Trace to a StringConvert File to byte array and Vice-VersaConvert InputStream to StringConvert OutputStream to StringLookup enum by String valueCompare StringsSort ArrayList of Custom Objects By PropertyCheck if a String is NumericJava Code To Create Pyramid and Pattern
To understand this example, you should have the knowledge of the following Java programming topics:
Programs to print triangles using *, numbers, and characters
Example 1: Program to print half pyramid using *
*
* *
* * *
* * * *
* * * * *
Source code
public class Main {
public static void main(String[] args) {
int rows = 5;
for (int i = 1; i <= rows; ++i) {
for (int j = 1; j <= i; ++j) {
System.out.print("* ");
}
System.out.println();
}
}
}
Example 2: Program to print half pyramid a using numbers
1
1 2
1 2 3
1 2 3 4
1 2 3 4 5
Source Code
public class Main {
public static void main(String[] args) {
int rows = 5;
for (int i = 1; i <= rows; ++i) {
for (int j = 1; j <= i; ++j) {
System.out.print(j + " ");
}
System.out.println();
}
}
}
Example 3: Program to print half pyramid using alphabets
A
B B
C C C
D D D D
E E E E E
Source Code
public class Main {
public static void main(String[] args) {
char last = 'E', alphabet = 'A';
for (int i = 1; i <= (last - 'A' + 1); ++i) {
for (int j = 1; j <= i; ++j) {
System.out.print(alphabet + " ");
}
++alphabet;
System.out.println();
}
}
}
Programs to print inverted half pyramid using * and numbers
Example 4: Inverted half pyramid using *
* * * * *
* * * *
* * *
* *
*
Source Code
public class Main {
public static void main(String[] args) {
int rows = 5;
for (int i = rows; i >= 1; --i) {
for (int j = 1; j <= i; ++j) {
System.out.print("* ");
}
System.out.println();
}
}
}
Example 5: Inverted half pyramid using numbers
1 2 3 4 5
1 2 3 4
1 2 3
1 2
1
Source Code
public class Main {
public static void main(String[] args) {
int rows = 5;
for (int i = rows; i >= 1; --i) {
for (int j = 1; j <= i; ++j) {
System.out.print(j + " ");
}
System.out.println();
}
}
}
Programs to display pyramid and inverted pyramid using * and digits
Example 6: Program to print full pyramid using *
*
* * *
* * * * *
* * * * * * *
* * * * * * * * *
Source Code
public class Main {
public static void main(String[] args) {
int rows = 5, k = 0;
for (int i = 1; i <= rows; ++i, k = 0) {
for (int space = 1; space <= rows - i; ++space) {
System.out.print(" ");
}
while (k != 2 * i - 1) {
System.out.print("* ");
++k;
}
System.out.println();
}
}
}
Example 7: Program to print pyramid using numbers
1
2 3 2
3 4 5 4 3
4 5 6 7 6 5 4
5 6 7 8 9 8 7 6 5
Source Code
public class Main {
public static void main(String[] args) {
int rows = 5, k = 0, count = 0, count1 = 0;
for (int i = 1; i <= rows; ++i) {
for (int space = 1; space <= rows - i; ++space) {
System.out.print(" ");
++count;
}
while (k != 2 * i - 1) {
if (count <= rows - 1) {
System.out.print((i + k) + " ");
++count;
} else {
++count1;
System.out.print((i + k - 2 * count1) + " ");
}
++k;
}
count1 = count = k = 0;
System.out.println();
}
}
}
Example 8: Inverted full pyramid using *
* * * * * * * * *
* * * * * * *
* * * * *
* * *
*
Source Code
public class Main {
public static void main(String[] args) {
int rows = 5;
for(int i = rows; i >= 1; --i) {
for(int space = 1; space <= rows - i; ++space) {
System.out.print(" ");
}
for(int j=i; j <= 2 * i - 1; ++j) {
System.out.print("* ");
}
for(int j = 0; j < i - 1; ++j) {
System.out.print("* ");
}
System.out.println();
}
}
}
Example 9: Print Pascal’s triangle
1
1 1
1 2 1
1 3 3 1
1 4 6 4 1
1 5 10 10 5 1
Source Code
public class Main {
public static void main(String[] args) {
int rows = 6, coef = 1;
for(int i = 0; i < rows; i++) {
for(int space = 1; space < rows - i; ++space) {
System.out.print(" ");
}
for(int j = 0; j <= i; j++) {
if (j == 0 || i == 0)
coef = 1;
else
coef = coef * (i - j + 1) / j;
System.out.printf("%4d", coef);
}
System.out.println();
}
}
}
Example 10: Print Floyd’s Triangle.
1
2 3
4 5 6
7 8 9 10
Source Code
public class Main {
public static void main(String[] args) {
int rows = 4, number = 1;
for(int i = 1; i <= rows; i++) {
for(int j = 1; j <= i; j++) {
System.out.print(number + " ");
++number;
}
System.out.println();
}
}
}