1、使用equals( )方法比較兩個字符串是否相等（區分大小寫）
2、使用equalsIgnoreCase( )方法比較兩個字符串是否相等（不區分大小寫）
boolean equalsIgnoreCase(String str)
下面的例子說明了equals( )和equalsIgnoreCase( )方法：
class equalsTest {
public static void main(String args[]) {
String s1 = "Hello";
String s2 = "Hello";
String s3 = "HELLO";
System.out.println(s1 + " equals " + s2 + " -> " + s1.equals(s2));
System.out.println(s1 + " equals " + s3 + " -> " + s1.equals(s3));
System.out.println(s1 + " equalsIgnoreCase " + s3 + " -> " + s1.equalsIgnoreCase(s3));
}
}
該程序的輸出如下所示：
Hello equals Hello -> true
Hello equals HELLO -> false
Hello equalsIgnoreCase HELLO -> true