C++: A Dialog Programming with the C++ Standard Library

Index Variables

Now let's get back to our discussion of the revised pumpkin-weighing program. The last two lines in the variable definition phase define two variables, called i and k, which have been traditional names for index variables (i.e., variables used to hold indexes) since the invention of FORTRAN, one of the first relatively “user-friendly” computer languages, in the 1950s. The inventors of FORTRAN used a fairly simple method of determining the type of a variable: if it began with one of the letters I through N, it was an integer. Otherwise, it was a floating-point variable (i.e., one that can hold values that contain a fractional part, such as 3.876). This rule was later changed so that the user could specify the type of the variable ...