1. Learn
    2. /
  2. Courses
    3. /
  3. Optimizing R Code with Rcpp

Exercise

if and if/else

Just like in R, you can use the if and else keywords for branching. The syntax is the same as in R.

if(condition) {
  // Code to run if the condition is TRUE
} else {
  // Code to run otherwise
}

Here you'll use if and else to complete the definition of an absolute() function to calculate the absolute value of a floating point number. (This mimics the C++ function fabs().)

Instructions

100 XP
  • Test if x is greater than zero.
  • If the condition holds, return x.
  • Add the keyword for what to do otherwise.
  • If the condition doesn't hold, return negative x.