Java Practice · ⁨Java 练习⁩

Every lesson runs in your browser — write real code, press Run, and the tasks check themselves. Free, no account needed, with translated notes paired with English. · ⁨每节课均在浏览器中运行——编写真实代码，点击运行，任务自动检查。免费，无需账户，配有与英文对照的翻译笔记。⁩

Start the course · ⁨开始课程⁩

Lessons in this course · ⁨本课程中的课程⁩

No lessons match. Clear the search or choose another filter. · ⁨没有匹配的课时。请清空搜索或选择其他筛选条件。⁩

1. 01 Print a word · ⁨打印一个单词⁩ 1 required task · ⁨1 个必做任务⁩ · ★
2. 02 Print another word · ⁨再打印一个单词⁩ 1 required task · ⁨1 个必做任务⁩ · ★
3. 03 Print a sentence · ⁨打印一句话⁩ 1 required task · ⁨1 个必做任务⁩ · ★
4. 04 Print with a ! · ⁨用感叹号打印⁩ 1 required task · ⁨1 个必做任务⁩ · ★
5. 05 Print two lines · ⁨打印两行⁩ 1 required task · ⁨1 个必做任务⁩ · ★
6. 06 Print a number · ⁨打印一个数字⁩ 1 required task · ⁨1 个必做任务⁩ · ★
7. 07 Add two numbers · ⁨两数相加⁩ 1 required task · ⁨1 个必做任务⁩ · ★
8. 08 Subtract · ⁨减法⁩ 1 required task · ⁨1 个必做任务⁩ · ★
9. 09 Multiply · ⁨乘法⁩ 1 required task · ⁨1 个必做任务⁩ · ★
10. 10 Divide · ⁨除法⁩ 1 required task · ⁨1 个必做任务⁩ · ★
11. 11 Remainder · ⁨求余数⁩ 1 required task · ⁨1 个必做任务⁩ · ★
12. 12 A number variable · ⁨数字变量⁩ 1 required task · ⁨1 个必做任务⁩ · ★
13. 13 A text variable · ⁨文字变量⁩ 1 required task · ⁨1 个必做任务⁩ · ★
14. 14 Add two variables · ⁨变量相加⁩ 1 required task · ⁨1 个必做任务⁩ · ★
15. 15 Your first method · ⁨你的第一个方法⁩ 1 required task · ⁨1 个必做任务⁩ · ★
16. 16 Is it positive? · ⁨是正数吗?⁩ 1 required task · ⁨1 个必做任务⁩ · ★
17. 17 Cube a number · ⁨求立方⁩ 1 required task · ⁨1 个必做任务⁩ · ★
18. 18 The smaller one · ⁨较小的那个⁩ 1 required task · ⁨1 个必做任务⁩ · ★
19. 19 Square a number · ⁨求平方⁩ 1 required task · ⁨1 个必做任务⁩ · ★
20. 20 Largest of three · ⁨三者中的最大值⁩ 1 required task · ⁨1 个必做任务⁩ · ★
21. 21 Count the vowels · ⁨数元音字母⁩ 1 required task · ⁨1 个必做任务⁩ · ★★
22. 22 Reverse the word order · ⁨反转单词顺序⁩ 1 required task · ⁨1 个必做任务⁩ · ★★
23. 23 Palindrome check · ⁨回文判断⁩ 1 required task · ⁨1 个必做任务⁩ · ★★★
24. 24 Running sum · ⁨前缀和⁩ 1 required task · ⁨1 个必做任务⁩ · ★★★
25. 25 Most frequent character · ⁨出现最多的字符⁩ 1 required task · ⁨1 个必做任务⁩ · ★★★
26. 26 Binary search · ⁨二分查找⁩ 1 required task · ⁨1 个必做任务⁩ · ★★★
27. 27 Factorial (mind the size) · ⁨阶乘(注意大小)⁩ 1 required task · ⁨1 个必做任务⁩ · ★★★★
28. 28 Count primes below n · ⁨数小于 n 的质数⁩ 1 required task · ⁨1 个必做任务⁩ · ★★★★
29. 29 Roman numerals · ⁨罗马数字⁩ 1 required task · ⁨1 个必做任务⁩ · ★★★★★
30. 30 Longest common prefix · ⁨最长公共前缀⁩ 1 required task · ⁨1 个必做任务⁩ · ★★★★★

Language reference · ⁨语言参考⁩

/know/reference/java