Given a string, write a function that converts it either from lower to upper case or from upper to lower case using the bitwise operators &(AND), |(OR), ~(NOT) in place and returns the string.
Many of us know that Bitwise manipulations are faster than performing arithmetic operations for a compiler as the data is stored in binary form 0’s and 1’s.
Input : "LowerToUpPer" Output : "LOWERTOUPPER" Letters already in the uppercase remains the same. while rest get converted to uppercase. Input : "UPPerTOloweR" Output : "uppertolower" Letters already in the lowercase remains the same. while rest get converted to lowercase.
1.Lower to Upper Case
This method simply subtracts a value of 32 from the ASCII value of lowercase letter by Bitwise ANDing (&) with negation (~) of 32 converting the letter to uppercase.
2.Upper to Lower Case
Similarly, it adds a value of 32 to the ASCII value of uppercase letter by Bitwise ORing (|) with 32 converting the letter to lowercase.
The ASCII table is constructed in such way that the binary representation of lowercase letters is almost identical of binary representation of uppercase letters.
Character ‘A’ is integer 65 = (0100 0001)2, while character ‘a’ is integer 97 = (0110 0001)2.
The difference between the ASCII values of ‘a’ and ‘A’ is 32.
So we can easily change the case of the letters either from Upper to lower or lower to upper by adding or subtracting the difference from the letters using bitwise operators as shown above.
Implement a function that change the case of a string such that GeeksFoRgeekS turns gEEKSfOrGEEKs .
This article is contributed by Sanjay Kumar Ulsha from JNTUH College Of Engineering, Hyderabad. If you like GeeksforGeeks and would like to contribute, you can also write an article using contribute.geeksforgeeks.org or mail your article to email@example.com. See your article appearing on the GeeksforGeeks main page and help other Geeks.
Please write comments if you find anything incorrect, or you want to share more information about the topic discussed above.
- Lower case to upper case - An interesting fact
- Toggle case of a string using Bitwise Operators
- Check whether the given character is in upper case, lower case or non alphabetic character
- Alternate Lower Upper String Sort
- Python String Methods | Set 1 (find, rfind, startwith, endwith, islower, isupper, lower, upper, swapcase & title)
- Program to convert speed in km/hr to m/sec and vice versa
- Program to Convert Km/hr to miles/hr and vice versa
- Substrings starting with vowel and ending with consonants and vice versa
- Program to print Lower triangular and Upper triangular matrix of an array
- Sum of upper triangle and lower triangle
- Decimal to octal conversion with minimum use of arithmetic operators
- Minimum number of operations to move all uppercase characters before all lower case characters
- Bitwise Operators in C/C++
- Bitwise operators in Java
- Check if a Number is Odd or Even using Bitwise Operators