通过字符串函数 compareTo (string) ,compareToIgnoreCase(String) 及 compareTo(object string) 来比较两个字符串,并返回字符串中第一个字母ASCII的差值
```java
```java
public class StringCompare {
public static void main(String args[]){
String str = "Hello World";
String str2 = "hello world";
String str3 = "hello yzh";
String str4 = "hello yzha";
Object objStr = str2;
System.out.println( str.compareTo(str2) );
System.out.println( str2.compareTo(str3) );
System.out.println( str3.compareTo(str4) );
System.out.println( str.compareToIgnoreCase(str2) );
System.out.println( str2.compareToIgnoreCase(str3) );
System.out.println( str3.compareToIgnoreCase(str4) );
System.out.println( str.compareTo(objStr.toString()));
}
}
