Need explanation

(a) Write a for loop that prints a null-terminated string character-by-character to standard output. (b) Write a while loop that takes the sum of every other element in an integer array (starting from element 0). (c) Write a switch statement that calculates and prints a + b if a character is ' + '; calculates and prints a - b if a character is ' - '; calculates and prints a * b if a character is ' * '; calculates and prints a/b if a character is '/'; and prints "Unknown operator. " otherwise. (d) Write an if-else statement that checks if a character is a digit ('0' - '9') or a letter ('a' - 'z' and 'A' - 'Z'). If it is a digit, print "The character is a digit. "; if it is a letter, print "The character is a letter. "; otherwise, print "It is a non alphanumeric character