Consider the following prototype of the C$++$ function that computes and returns the sum ofall digits in the decimal representation of an integer value m$.$int sumOfDigits$($int m$)$;For example, the sum of digits in $1234$ is $1+2+3+4=10.$ That means, if the input to the function is$1234,$ the function returns $10.$ Similarly, if the input to the function is $-1234,$ the function returns $-10.$Implement the function in C$++.$