A function can be called from different places, maybe it will be used in code not yet written. So a programmer has a need to print every line. The code to be ch

A function can be called from different places, maybe it will be used in code not yet written. So a programmer has a need to print every line. The code to be changed calls printEveryOtherLine. They won't change that function to print every line, because they know that would break things elsewhere.