# Java 程序：按字典顺序对元素进行排序 > 原文： [https://www.programiz.com/java-programming/examples/lexicographical-order-words](https://www.programiz.com/java-programming/examples/lexicographical-order-words) #### 在此程序中，您将学习使用`for`循环以及`if-else`按字典顺序对元素词进行排序。 ## 示例：按字典顺序对字符串排序的程序 ```java public class Sort { public static void main(String[] args) { String[] words = { "Ruby", "C", "Python", "Java" }; for(int i = 0; i < 3; ++i) { for (int j = i + 1; j < 4; ++j) { if (words[i].compareTo(words[j]) > 0) { // swap words[i] with words[j[ String temp = words[i]; words[i] = words[j]; words[j] = temp; } } } System.out.println("In lexicographical order:"); for(int i = 0; i < 4; i++) { System.out.println(words[i]); } } } ``` 运行该程序时，输出为： ```java In lexicographical order: C Java Python Ruby ``` 在上述程序中，要排序的 5 个单词的列表存储在变量`word`中。 然后，我们遍历每个单词（`words[i]`），并将其与数组中之后的所有单词（`words[j]`）进行比较。 这是通过使用字符串的`compareTo()`方法完成的。 如果`compareTo()`的返回值大于 0，则必须在位置上进行交换，即`word[i]`在`word[j]`之后。 因此，在每次迭代中，`word[i]`包含最早的单词。 执行步骤 | 迭代 | 初始词 | `i` | `j` | `word[]` | | --- | --- | --- | --- | --- | | 1 | `{ "Ruby", "C", "Python", "Java" }` | 0 | 1 | `{ "C", "Ruby", "Python", "Java" }` | | 2 | `{ "C", "Ruby", "Python", "Java" }` | 0 | 2 | `{ "C", "Ruby", "Python", "Java" }` | | 3 | `{ "C", "Ruby", "Python", "Java" }` | 0 | 3 | `{ "C", "Ruby", "Python", "Java" }` | | 4 | `{ "C", "Ruby", "Python", "Java" }` | 1 | 2 | `{ "C", "Python", "Ruby", "Java" }` | | 5 | `{ "C", "Python", "Ruby", "Java" }` | 1 | 3 | `{ "C", "Java", "Ruby", "Python" }` | | 最后 | `{ "C", "Java", "Ruby", "Python" }` | 2 | 3 | `{ "C", "Java", "Python", "Ruby" }` |