Programming in Objective-C, Sixth Edition

Data Type Conversions

Chapter 4, “Data Types and Expressions,” briefly addressed the fact that sometimes the system implicitly makes conversions when expressions are evaluated. You examined a case with the data types float and int. You saw how an operation that involves a float and an int was carried out as a floating-point operation, with the integer data item automatically converted to a floating point.

You also saw how the type cast operator can be used to explicitly dictate a conversion. So given that total and n are both integer variables

average = (float) total / n;

the value of the variable total is converted to type float before the operation is performed, thereby guaranteeing that the division will be carried out as a floating-point ...