Tutorial Playlist
191 Lessons1. Introduction to Java
2. What is Java?
3. History of Java
4. Java Tutorial for Beginners
5. How Do Java Programs Work?
6. JDK in Java
7. C++ Vs Java
8. Java vs. Python
9. Java vs. JavaScript
10. From Java Source Code to Executable
11. How to Install Java in Linux
12. How to Install Java in Windows 10
13. Java Hello World Program
14. Structure of Java Program and Java Syntax
15. Operators in Java
16. Java If-else
17. Switch Case In Java
18. Loops in Java
Now Reading
19. Infinite loop in Java
20. For Loop in Java
21. For Each Loop in Java
22. Constructor in Java
23. Constructor Overloading in Java
24. Copy Constructor in Java
25. Default Constructor in Java
26. Parameterized Constructors in Java
27. Constructor Chaining In Java
28. Finalize Method in Java
29. Static Method in Java
30. Equals Method in Java
31. Abstract Method in Java
32. toString() Method in Java
33. Difference between equals method in Java
34. Inheritance in Java
35. Multiple Inheritance in Java
36. Hierarchical Inheritance in Java
37. Java Classes and Objects
38. Scanner Class in java
39. All classes in java are inherited from which class
40. What is Nested Class in Java
41. POJO Class in Java
42. Anonymous Class in Java
43. Final Class in Java
44. Object Class in Java
45. Packages in Java
46. Access Modifiers in Java
47. Static Keyword In Java
48. Final Keyword in Java
49. Checked and Unchecked Exceptions in Java
50. User Defined Exception in Java
51. Error vs. Exception in Java
52. Java Collection
53. Collections in Java
54. Garbage Collection in Java
55. Generics In Java
56. Java Interfaces
57. Functional Interface in Java
58. Marker Interface in Java
59. Streams in Java
60. Byte stream in java
61. File Handling in Java
62. Thread in Java
63. Thread Lifecycle In Java
64. Daemon Thread in Java
65. Thread Priority in Java
66. Deadlock in Java
67. String Pool in Java
68. Java Database Connectivity(JDBC)
69. Design Patterns in Java
70. Functional Programming in Java
71. OOP vs Functional vs Procedural
72. Heap Memory and Stack Memory in Java
73. Applet in Java
74. Java Swing
75. Java Frameworks
76. Hibernate Framework
77. JUnit Testing
78. How to Install Eclipse IDE for Java?
79. Command line arguments in Java
80. Jar file in Java
81. Java Clean Code
82. OOPs Concepts in Java
83. Java OOPs Concepts
84. Overloading vs Overriding in Java
85. Java 8 features
86. String in Java
87. String to int in Java
88. Why String Is Immutable in Java?
89. Primitive Data Types in Java
90. Non-Primitive Data Types in Java
91. This and Super Keyword in Java
92. HashMap in Java
93. Comparable And Comparator in Java
94. Type Casting in Java
95. Arrays Sort in Java with Examples
96. Variable Hiding and Variable Shadowing in Java
97. Enum in Java
98. Substring in Java
99. Pattern Programs in Java
100. Hashcode in Java
101. What is ByteCode in Java?
102. How To Take Input From User in Java
103. GCD of Two Numbers in Java
104. Linked List in Java
105. Arithmetic Operators in Java
106. Conditional Operators in Java
107. Stack and Queue in Java
108. Array Length in Java
109. Number Pattern Program in Java
110. Split in java
111. Map In Java
112. Difference Between Throw and Throws in Java
113. Difference Between Data Hiding and Abstraction
114. HashSet in Java
115. String Length in Java
116. Factorial Using Recursion in Java
117. DateFormat in Java
118. StringBuilder Class in java
119. Instance variables in Java
120. Java List Size
121. Java APIs
122. Reverse an Array in Java
123. StringBuffer and StringBuilder Difference in Java
124. Java Program to Add Two Numbers
125. String to Array in Java
126. Regular Expressions in Java
127. Identifiers in Java
128. Data Structures in Java
129. Set in Java
130. Pass By Value and Call By Reference in Java
131. Try Catch in Java
132. Bubble Sort in Java
133. Caesar Cipher Program in Java
134. Queue in Java
135. Object Creation in Java
136. Multidimensional Array in Java
137. How to Read a File in Java
138. String Comparison in Java
139. Volatile Keyword in Java
140. Control Statements in Java
141. Jagged Array in Java
142. Two-Dimensional Array in Java
143. Java String Format
144. Replace in Java
145. charAt() in Java
146. CompareTo in Java
147. Matrix Multiplication in Java
148. Static Variable in Java
149. Event Handling in Java
150. parseInt in Java
151. Java ArrayList forEach
152. Abstraction in Java
153. String Input in Java
154. Logical Operators in Java
155. instanceof in Java
156. Math Floor in Java
157. Selection Sort Java
158. int to char in Java
159. Stringtokenizer in java
160. Implementing and Manipulating Abs in Java
161. Char array to string in java
162. Convert Double To String In Java
163. Deque in Java
164. Converting a List to an Array in Java
165. The Max function in java
166. Removing whitespace from string in java
167. String arrays in Java
168. Strings in Java Vs Strings in Cpp
169. Sum of digits of a number in Java
170. Art of Graphical User Interfaces
171. Trim in Java
172. RxJava
173. Recursion in Java
174. HashSet Java
175. Difference Between Java and Python
176. Square Root in Java
177. Reverse A String in Java
178. Even Odd Program in Java
179. Fibonacci Series in Java
180. Prime Number Program in Java
181. Java Program to Print Prime Numbers in a Given Range
182. Java Leap Year Program
183. Swapping of Two Numbers in Java
184. LCM of Two Numbers in Java
185. Math.sqrt() Function in Java
186. Area of Triangle in Java
187. Sort a String In Java
188. Factorial Program in Java
189. Javafx
190. Lambda expression in java
191. Setup Java Home and IDE on macOS
In Java programming, loops play a crucial role in controlling the flow of execution by allowing repetitive tasks to be performed efficiently. By using loops, you can iterate over collections, repeat statements based on certain conditions, and execute code blocks a specific number of times. In this article, we will explore the various types of loops in Java with examples, including the while loop, do while loop, for loop, and for-each loop. By the end, you will have a solid understanding of each loop construct and how to utilize it effectively in your Java programs.
The while loop in Java is a pre-test loop in Java. It checks the condition before executing the loop body. If the condition is true, the loop body is executed, and then the condition is checked again. This process continues until the condition is evaluated as false. The while loop is suitable when the number of iterations is uncertain or when you want to repeatedly execute a block of code based on a specific condition. The general syntax of a while loop is as follows:
Syntax:
Example:
Output:
The do while loop in Java is a post-test loop in Java. Before checking the condition, it runs the loop's body. The process continues if the condition is satisfied, and the loop body is run once more. Until the condition is evaluated as false, the loop keeps running. When you want to guarantee that the loop body gets run at least once, regardless of the condition, the do-while loop is helpful. Let’s look at the syntax for a do-while loop.
Syntax:
Example:
Output:
Java has a flexible looping mechanism called the for loop. It enables fine-grained control over the startup, condition, and update phases of the loop. The for loop is often used when you need to iterate over a range of variables or when you know exactly how many iterations you will need in advance. The condition check is carried out after the initialization phase. The update step is carried out after the loop's body has been executed if the condition is true. Up until the condition is evaluated as false, the process is repeated. A post-test loop in Java is the do-while loop. Before checking the condition, it runs the loop's body. The process continues if the condition is satisfied, and the loop body is run once more. Until the condition is evaluated as false, the loop keeps running. When you want to guarantee that the loop body gets run at least once, regardless of the condition, the do-while loop is helpful. The general syntax is as follows:
Syntax:
Example:
Output:
The for-each loop, introduced in Java 5, facilitates array and collection iteration. It maintains the iteration automatically and provides an easy way to access each element without the need for explicit indexing. The for-each loop loops through the elements of the provided array or collection, assigning the current element to a loop variable. The body of the loop is then executed for each element. This loop comes in handy when you want to iterate over all elements of an array or collection without having to bother with indices. The for-each loop in Java has the following general syntax.
Syntax:
Example:
Output:
Nested loops in Java refer to the concept of having one loop inside another loop. This allows for the execution of complex iterations and the efficient handling of multi-dimensional data structures. The outer loop controls the iteration of the inner loop, creating a nested structure. By nesting loops, you can perform repetitive tasks on each element or combination of elements within the nested data structure.
Let’s consider the following example:
Output:
Nested loops can be implemented using any of the loop constructs in Java: while, do-while, for, or for-each. The inner loop's iteration depends on the outer loop's iteration. For each iteration of the outer loop, the inner loop executes its own set of iterations, repeating until the inner loop's termination condition is met. Once the inner loop is complete, the outer loop proceeds to its next iteration.
When working with multi-dimensional arrays, matrices, or nested collections, nested loops are widely employed. They enable you to process elements within the nested structure row by row, column by column, or in any desired pattern. You can perform operations on the elements, such as searching, sorting, filtering, or computations, by carefully regulating the iteration of nested loops.
When working with nested loops, it's crucial to be cautious because they can quickly cause performance concerns if not constructed properly. Make sure to optimize the loop structure and avoid iterations that are unneeded or redundant.
An infinite loop is a loop that continues to execute indefinitely without terminating. It occurs when the loop condition always evaluates to true or when there is no condition specified. Infinite loops can be unintentional and often lead to programs freezing or crashing, so they should be avoided unless intentionally used in certain scenarios.
Here are a few common ways an infinite loop can occur:
1. Missing or Incorrect Termination Condition: If the loop condition is not properly defined or accidentally omitted, the loop will continue indefinitely. For example:
2. Improper Update or Increment: If the loop update or increment statement is missing or incorrect, the loop condition may never change, causing an infinite loop. For example:
3. Endless Loop Constructs: Certain loop constructs, such as the `while (true)` or `for (;;)`, are intentionally designed to create infinite loops. These constructs are used when specific termination conditions are not applicable or when the loop is meant to run indefinitely until explicitly terminated.
To avoid unintended infinite loops, loop conditions must be properly defined and eventually evaluated as false. If an infinite loop is intended, incorporate suitable control statements within the loop, such as 'break' or 'return' to escape it as necessary.
Nested loops allow you to conduct sophisticated iterations over multi-dimensional data structures. However, in order to avoid performance concerns, their structure must be optimized. Infinite loops, on the other hand, can cause programs to freeze or crash, so they should be handled with care.
When working with large data sets, it's critical to optimize your loops to minimize performance impacts. Consider the following methods:
You may increase the efficiency of your loops when working with huge data sets in Java by using these optimization strategies.
Loops in Java are widely used in various real-world scenarios to automate repetitive tasks, iterate over collections, process data, and handle complex logic. Here are a few examples of practical scenarios where loops in Java can be applied:
Loops let you perform particular operations on each item in lists, arrays, and maps. A for-each loop can calculate the total price or display product data for an array of products.
Loops can be used to constantly ask users for correct input. A while loop or do-while loop can repeatedly remind the user and check the input against particular requirements until it is valid.
When reading data from a file or writing data to a file, loops can be used to iterate through the file content and perform operations on each line or record. For example, you can read a CSV file line by line using a while loop and process the data accordingly.
In report generation scenarios, loops are often used to iterate over a dataset or a collection of records and generate reports with aggregated or summarized information. You can use a for loop or a for-each loop to iterate through the data and generate the required report.
Loops handle incoming connections and process network data in network programming. A server program might use a while loop to listen for requests, process them, and deliver responses until explicitly ended.
Loops are essential in game development to handle game logic, update game states, and process user input. Game loops typically run continuously, repeatedly updating the game world, handling collisions, and rendering graphics until the game is exited.
Loops run through values, calculate, and provide results in scientific and mathematical operations. You can use a for loop to calculate mathematical sequences or simulate them numerically.
These are some examples of real-world Java loop usage. Loops simplify repeated operations, handle vast amounts of data, and perform sophisticated algorithms in numerous disciplines.
Output:
1
2
3
4
5
6
7
8
9
10
Output:
The output of the given code depends on the input provided by the user. Here's an example of the output for different inputs:
Example 1:
Enter a number: 5
Sum: 15
Example 2:
Enter a number: 10
Sum: 55
Example 3:
Enter a number: 3
Sum: 6
In each case, the program prompts the user to enter a number. It then calculates the sum of all numbers from 1 to the entered number (inclusive) using a for loop. The final output displays the calculated sum.
Output:
The user's input determines the output of the given code in this instance as well. Here are some examples of the output for different inputs:
Example 1:
Enter the number of rows: 5
1
1 2
1 2 3
1 2 3 4
1 2 3 4 5
Example 2:
Enter the number of rows: 3
1
1 2
1 2 3
Example 3:
Enter the number of rows: 7
1
1 2
1 2 3
1 2 3 4
1 2 3 4 5
1 2 3 4 5 6
1 2 3 4 5 6 7
The programme always asks for the row count. Nested loops print a pattern with numbers from 1 to the row number. Input determines the output pattern.
Loops are an essential component of Java programming because they make it possible to carry out repetitive operations in an easy and effective manner. The while loop, the do-while loop, the for loop, and the for-each loop each offer a unique method of controlling the iteration, making them useful in a wide variety of programming contexts. Learning to use these loop components effectively will allow you to write strong and adaptable programs. Always remember to test and debug your code to ensure that it works properly, and choose the loop type that is most appropriate for your needs by basing your decision on those requirements.
1. How do you break out of a loop in Java?
Java's break statement breaks loops. The `break` statement leaves a loop and starts the following sentence.
2. Which loop in Java is faster?
Due to the fact that the for-each is implemented by the iterator and requires concurrent mutation verification, the for-loop approach is quicker when utilizing an ArrayList.
3. What do you mean by loop statements?
A program loop is a collection of statements that run repeatedly for a predetermined period of time or until certain criteria are satisfied.
PAVAN VADAPALLI
Director of Engineering
Director of Engineering @ upGrad. Motivated to leverage technology to solve problems. Seasoned leader for startups and fast moving orgs. Working …Read More
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upGrad does not grant credit; credits are granted, accepted or transferred at the sole discretion of the relevant educational institution offering the diploma or degree. We advise you to enquire further regarding the suitability of this program for your academic, professional requirements and job prospects before enr...