# Java 程序：查找字符串中字符的出现 > 原文： [https://beginnersbook.com/2019/04/java-program-to-find-the-occurrence-of-a-character-in-a-string/](https://beginnersbook.com/2019/04/java-program-to-find-the-occurrence-of-a-character-in-a-string/) 在本教程中，我们将编写一个 Java 程序来查找`String`中字符的出现。 ## 编程以查找字符串中字符的出现 在这个程序中，我们发现`String`中每个字符的出现。为此，我们首先创建一个大小为 256（ASCII 上限）的数组，这里的想法是将出现次数存储在该字符的 ASCII 值中。例如，`'A'`的出现将存储在计数器[65]中，因为`A`的 ASCII 值是 65，类似地，其他字符的出现存储在它们的 ASCII 索引值中。 然后我们创建另一个数组`array`来保存给定`String`的字符，然后我们将它们与`String`中的字符进行比较，当找到匹配时，使用`counter`数组显示该特定字符的计数。 ```java class JavaExample { static void countEachChar(String str) { //ASCII values ranges upto 256 int counter[] = new int[256]; //String length int len = str.length(); /* This array holds the occurrence of each char, For example * ASCII value of A is 65 so if A is found twice then * counter[65] would have the value 2, here 65 is the ASCII value * of A */ for (int i = 0; i < len; i++) counter[str.charAt(i)]++; // We are creating another array with the size of String char array[] = new char[str.length()]; for (int i = 0; i < len; i++) { array[i] = str.charAt(i); int flag = 0; for (int j = 0; j <= i; j++) { /* If a char is found in String then set the flag * so that we can print the occurrence */ if (str.charAt(i) == array[j]) flag++; } if (flag == 1) System.out.println("Occurrence of char " + str.charAt(i) + " in the String is:" + counter[str.charAt(i)]); } } public static void main(String[] args) { String str = "beginnersbook"; countEachChar(str); } } ``` **输出：**  #### 相关的 Java 程序 1. [Java 程序：按字母顺序排序字符串](https://beginnersbook.com/2018/10/java-program-to-sort-strings-in-an-alphabetical-order/) 2. [Java 程序：检查元音和辅音](https://beginnersbook.com/2017/09/java-program-to-check-vowel-and-consonant-using-switch-case/) 3. [Java 程序：查找字符串中的重复字符](https://beginnersbook.com/2014/07/java-program-to-find-duplicate-characters-in-a-string/) 4. [Java 程序：检查回文串](https://beginnersbook.com/2014/01/java-program-to-check-palindrome-string-using-recursion/)