Question

java笔试(写一个类,实现接口并实现反转字符串的功能)

现在有一个interface定义如下:
Interface inverseString{
Public String inverseString(String s);
}
写一个类,实现inverseString接口,并实现反转字符串的功能.

Answer 1

interface inverseString{
public String inverseString(String s);
}
class Inttest implements inverseString{
public String inverseString(String s){
char[] a=new char[s.length()];
char[] b=new char[s.length()];
s.getChars(0,s.length(),a,0);
for(int i=0;i<s.length();i++){
int j=s.length()-1;
b[j]=a[i];
j--;
}
return new String(b);
}
}

Answer 2

public class InverseStringImp implements inverseString{
public String inverseString(String s)
{
if (s == null)
{
return;
}
StringBuffer sb =new StringBuffer();
for (int i = s.length; i >= 0;i--)
{
sb.append(s.charAt(i));
}
return sb.toString();
}
}

Answer 3

public String inverseString(String s){
char[] ch=s.toCharArray();
String t="";
int len=ch.length;
for(int i=len-1;i>=0;i--){
t+=String.valueOf(ch[i]);
}
return t;

}