Reverse of String means reverse the position of all character of any String. For example reverse of porter is retrop.
Reverse a String in C++
#include<iostream.h> #include<stdio.h> #include<conio.h> #include<string.h> void main() { char str[100],temp; int i,j=0; clrscr(); cout<<"Enter any the string :"; gets(str); // gets function for input string i=0; j=strlen(str)-1; while(i<j) { temp=str[i]; str[i]=str[j]; str[j]=temp; i++; j--; } cout<<"Reverse string is: "<<str; getch(); }
Output
Enter any the string : hitesh Reverse string is : hsetih
Explanation Of Program :
Firstly find the length of the string using library function strlen().
Code
j = strlen(str)-1;
Suppose we accepted String "hitesh" then
Code
j = strlen(str)-1; = strlen("hitesh") - 1 = 7 - 1 = 6
As we know String is charracter array and Character array have character range between 0 to length-1. Thus we have position of last character in variable 'j'.Current Values of 'i' and 'j' are :
Code
i = 0; j = 6;
'i' positioned on first character and 'j' positioned on last character. Now we are swapping characters at position 'i' and 'j'. After interchanging characters we are incrementing value of 'i' and decrementing value of 'j'.
Code
while(i<j) { temp = str[i]; str[i] = str[j]; str[j] = temp; i++; j--; }
If i crosses j then process of interchanging character is stopped.
