# Java 程序：按字典順序對元素進行排序 > 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，您將學習使用`for`循環以及`if-else`按字典順序對元素詞進行排序。 ## 示例：按字典順序對字符串排序的程序 ```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]); } } } ``` 運行該程序時，輸出為： ```java In lexicographical order: C Java Python Ruby ``` 在上述程序中，要排序的 5 個單詞的列表存儲在變量`word`中。 然后，我們遍歷每個單詞（`words[i]`），并將其與數組中之后的所有單詞（`words[j]`）進行比較。 這是通過使用字符串的`compareTo()`方法完成的。 如果`compareTo()`的返回值大于 0，則必須在位置上進行交換，即`word[i]`在`word[j]`之后。 因此，在每次迭代中，`word[i]`包含最早的單詞。 執行步驟 | 迭代 | 初始詞 | `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" }` |