In this program first and last characters of string is compared one by one moving towards centre.
Here string is entered in the variable ‘st’ of type String by user.
Now string is converted into upper case by first for loop and saved in new string variable ‘str’, this is done to ignore the conditions when the entered string is like ‘RAcecar’,after converting ,it becomes like ‘RACECAR’.
In second for loop we take first and last characters of string and compare them,
if they are equal ‘if’ condition is not executed and looping countinuos by incrementing first and decrementing lastvariables
if they are not equal ‘if’ condition is executed and looping terminates through break statement and flag is assinged the vale 0
Now variable flag is compared for checking the Palindrome.