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Java Programming Exercises, Practice, Solution

Java Exercises

Java is the foundation for virtually every type of networked application and is the global standard for developing and delivering embedded and mobile applications, games, Web-based content, and enterprise software. With more than 9 million developers worldwide, Java enables you to efficiently develop, deploy and use exciting applications and services.

The best way we learn anything is by practice and exercise questions. Here you have the opportunity to practice the Java programming language concepts by solving the exercises starting from basic to more complex exercises. A sample solution is provided for each exercise. It is recommended to do these exercises by yourself first before checking the solution.

Hope, these exercises help you to improve your Java programming coding skills. Currently, following sections are available, we are working hard to add more exercises .... Happy Coding!

List of Java Exercises:

Note: If you are not habituated with Java programming you can learn from the following :

More to Come !

Popularity of Programming Language
Worldwide, Dec 2022 compared to a year ago:

`
Rank Change Language Share Trend
1 Python 28.34 % -1.0 %
2 Java 16.93 % -0.8%
3 Javascript 9.28 % +0.3%
4 C# 6.89 % -0.3%
5 C/C++ 6.64 % -0.3 %
6 PHP 5.19 % -1.0 %
7 R 3.98 % -0.1%
8 up arrow TypeScript 2.79 % +1.1%
9 up arrow Swift 2.23 % +0.6%
10 down arrow Objective-C 2.22% +0.1%
11 down arrow Go2.02% +0.7%
12 up arrow Rust 1.78 % +0.8%
13 down arrow Kotlin 1.71 % -0.0%
14 down arrow Matlab 1.61 % +0.0%
15 up arrow Ruby 1.12% +0.2%
16 down arrow VBA 1.08 % -0.1 %
17 Ada 0.96 % +0.2 %
18 up arrow Dart 0.85 % +0.4 %
19 down arrow Scala 0.69 % -0.0 %
20 up arrow Lua 0.65 % +0.3 %
21 down arrow Visual Basic 0.57 % -0.1 %
22 down arrow Abap 0.55 % +0.1 %
23 down arrow Perl 0.53 % +0.1 %
24 Groovy 0.36 % +0.0 %
25 Cobol 0.33 % +0.0 %
26 Haskell 0.25 % +0.0 %
27 up arrow Julia 0.24 % +0.0 %
28 down arrow Delphi/Pascal 0.2 % -0.0 %

Source : https://pypl.github.io/PYPL.html

TIOBE Index for December 2022

Dec 2022 Dec 2021 Change Programming Language Ratings Change
1 1 Python 16.66% +3.76%
2 2 C 16.56% +4.77%
3 4 up arrow C++ 11.94% +4.21%
4 3 down arrow Java 11.82% +1.70%
5 5 C# 4.92% -1.48%
6 6 Visual Basic 3.94% -1.46%
7 7 JavaScript 3.19% +0.90%
8 9 up arrow SQL 2.22% +0.43%
9 8 down arrow Assembly language 1.87% -0.38%
10 12 up arrow PHP 1.62% +0.12%
11 11 R 1.25% -0.34%
12 19 up arrow Go 1.15% +0.20%
13 13 Classic Visual Basic 1.15% -0.13%
14 20 up arrow MATLAB 0.95% +0.03
15 10 down arrow Swift 0.91% -0.86%
16 16 Delphi/Object Pascal 0.85% -0.30%
17 15 down arrow Ruby 0.81% -0.35%
18 18 Perl 0.78% -0.18%
19 29 up arrow Objective-C 0.71% +0.29%
20 27 up arrow Rust 0.68% +0.23%

Source : https://www.tiobe.com/tiobe-index/

List of Exercises with Solutions :

[ Want to contribute to Java exercises? Send your code (attached with a .zip file) to us at w3resource[at]yahoo[dot]com. Please avoid copyrighted materials.]

Do not submit any solution of the above exercises at here, if you want to contribute go to the appropriate exercise page.



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Java: Tips of the Day

How to remove leading zeros from alphanumeric text?

Regex is the best tool for the job; what it should be depends on the problem specification. The following removes leading zeroes, but leaves one if necessary (i.e. it wouldn't just turn "0" to a blank string).

s.replaceFirst("^0+(?!$)", "")

The ^ anchor will make sure that the 0+ being matched is at the beginning of the input. The (?!$) negative lookahead ensures that not the entire string will be matched.

Test harness:

String[] in = {
    "01234",         // "[1234]"
    "0001234a",      // "[1234a]"
    "101234",        // "[101234]"
    "000002829839",  // "[2829839]"
    "0",             // "[0]"
    "0000000",       // "[0]"
    "0000009",       // "[9]"
    "000000z",       // "[z]"
    "000000.z",      // "[.z]"
};
for (String s : in) {
    System.out.println("[" + s.replaceFirst("^0+(?!$)", "") + "]");
}

Ref: https://bit.ly/2Qdcl8a