public class StringTry2 {
public static void main(String[] args) {
Scanner input=new Scanner(System.in);
System.out.println("请输入一个字符串");
String aaa=input.next();
for(int i=0;i<aaa.length();i++) {
System.out.println(aaa.charAt(i));
}
int bigCount=0;
int smallCount=0;
int numberCount=0;
for(int i=0;i<aaa.length();i++) {
char ch=aaa.charAt(i);
if(ch>=‘a‘&&ch<=‘z‘) {
smallCount++;
}else if(ch>=‘A‘&&ch<=‘Z‘) {
bigCount++;
}else if(ch>=‘1‘&&ch<=‘9‘) {
numberCount++;
}
}
System.out.println("大写字母"+bigCount+"小写字母"+smallCount+"数字"+numberCount);
}
}
public class StringBuilderTry {
public static void main(String[] args) {
StringBuilder sb=new StringBuilder();
sb.append(121214444).append(‘q‘);//链式编程，添加东西的方法
sb.reverse();//反转字符串
System.out.println(sb);
}
}
StringBuilder实现字符串反转：
ublic class StringBuilderTry02 {
public static void main(String[] args) {
// TODO Auto-generated method stub
Scanner input=new Scanner(System.in);
System.out.println("请输入一个字符串");
String s=input.next();
System.out.println("反转后："+Huan(s));
}
public static String Huan(String y) {
StringBuilder sb=new StringBuilder(y);
sb.reverse();
String ss=sb.toString();
return ss;
}
}
