day25-2将字符串的首字母转成大写,其他内容转成小写

package zuoye1;

public class zuoye1 {
public static void main(String[] args) {
a();
}
public static void a(){
String a1="aSdAsd";
String a2=a1.substring(0,1);
String b=a1.substring(1);
String a3=a2.toUpperCase();
String b1=b.toLowerCase();
System.out.print(a3);
System.out.println(b1);
}
}