Comparing Strings and Portions of Strings比较字符串和字符串的部分

The String class has a number of methods for comparing strings and portions of strings.String类有许多方法用于比较字符串和字符串的一部分。The following table lists these methods.下表列出了这些方法。

The following program, RegionMatchesDemo, uses the regionMatches method to search for a string within another string:以下程序RegionMatchesDemo使用regionMatches方法在另一个字符串中搜索字符串：

public class RegionMatchesDemo {
    public static void main(String[] args) {
        String searchMe = "Green Eggs and Ham";
        String findMe = "Eggs";
        int searchMeLength = searchMe.length();
        int findMeLength = findMe.length();
        boolean foundIt = false;
        for (int i = 0; 
             i <= (searchMeLength - findMeLength);
             i++) {
           if (searchMe.regionMatches(i, findMe, 0, findMeLength)) {
              foundIt = true;
              System.out.println(searchMe.substring(i, i + findMeLength));
              break;
           }
        }
        if (!foundIt)
            System.out.println("No match found.");
    }
}

The output from this program is Eggs.这个程序的输出是Eggs。

The program steps through the string referred to by searchMe one character at a time.程序一步一个字符地遍历searchMe引用的字符串。For each character, the program calls the regionMatches method to determine whether the substring beginning with the current character matches the string the program is looking for.对于每个字符，程序调用regionMatches方法来确定以当前字符开头的子字符串是否与程序正在查找的字符串匹配。