- in this exercise, please do not include and use string class. The function is using only array notation and manipulation.- string functions such as strlen is not allowed.- it should not have multiple return statements in the same function- there should be no global variable.- the function should not traverse the arrays more than once (e.g. looping through the array once only) A C++ PROGRAM named "changeCase" that takes an array of characters terminating by NULL character (C-string) and a boolean flag of toUpper. If the toUpper flag is true, it will go through the array and convert all lowercase characters to uppercase. Otherwise, it will convert all uppercase to lowercase. For example, if the array is {'H', 'e', 'l', 'l', 'o', '\0'} and the flag is true, then the array will become{'H', 'E', 'L', 'L', 'O', '\0'}. And if the flag is false, the array will become{'h', 'e', 'l', 'l', 'o', '\0'}