public static void main(String[] args) { int shuzi=48; String i = String.valueOf(shuzi); char c[] = new char[2]; c[0]=i.charAt(0); c[1]=i.charAt(1); String daox=""; for (int j = c.length-1; j >=0; j--) { daox=daox+c[j]; } int k=Integer.parseInt(daox); System.out.println(k); }
public class TestTest { public static void main(String[] args) { int num = 12; int reverse = num % 10 * 10 + num / 10; System.out.println(reverse); } }
最简单的:System.out.println(value/10 + value%10*10);
int num = 21; StringBuffer sb = new StringBuffer(); sb.append(num); System.out.println(sb.reverse().toString());
public static void main(String[] args) {
int shuzi=48;
String i = String.valueOf(shuzi);
char c[] = new char[2];
c[0]=i.charAt(0);
c[1]=i.charAt(1);
String daox="";
for (int j = c.length-1; j >=0; j--) {
daox=daox+c[j];
}
int k=Integer.parseInt(daox);
System.out.println(k);
}
int num = 12;
int reverse = num % 10 * 10 + num / 10;
System.out.println(reverse);
}
}
int num = 21;
StringBuffer sb = new StringBuffer();
sb.append(num);
System.out.println(sb.reverse().toString());
int test = 12;
System.out.println(new StringBuffer(String.valueOf(test)).reverse().toString());
试试这个
StringBuffer sb = new StringBuffer(Integer.toString(zs));
int ds=Integer.parseInt(sb.reverse().toString()) ;
System.out.print(ds);
int i = 12 ;
//第一种
System.out.println(new StringBuffer(String.valueOf(i)).reverse().toString()) ;
//第二种很强
System.out.println(i%10*10+i/10) ;
//第三种一开始就能想到的
String str = String.valueOf(i) ;
char[] t = new char[str.length()] ;
t = str.toCharArray() ;
str = "" ;
for (int _i=0;_i<=t.length-1;_i++) {
str += t[t.length-1-_i] ;
}
System.out.println(str) ;
//第四种substring
String _str = String.valueOf(i) ;
int len = _str.length() ;
for (int _i=0;_i<=len-1;_i++) {
System.out.println(_str.substring(len-1-_i,len-_i)) ;
}
}
}
再继续推算一下,很有意思:
假设有一个2位数10a+b,则有 10b + a = b + 9b + 10a - 9a = 10a + b + 9(b-a)
即 互换后的数 = 原数 + (个位数字 - 十位数字)× 9比如原数12,则有12 + (2 - 1)×9 = 21
原数91,则有91 + (1 - 9)×9 = 19借用5楼的代码:
public class TestTest { public static void main(String[] args) {
int num = 12;
int reverse = num + (num % 10 - num / 10)*9;
System.out.printf("%02d",reverse); //便于90 输出 09
}
}