Programming Languages: Concepts and Implementation

7.4 Type Conversion, Coercion, and Casting

Type conversion is the most general of these concepts, in that the other two concepts (i.e., casting and coercion) are instances of conversion. Conversion refers to either implicitly or explicitly changing a value from one data type to another. For instance, converting an integer into a floating-point number is an example of conversion. The storage requirements (e.g., from 32 bits to 64 bits) of a value may change as a result of conversion. Type conversions can be either implicit or explicit.

7.4.1 Type Coercion: Implicit Conversion

Coercion is an implicit conversion in which values can deviate from the type required by an operator or function without warning or error because the appropriate conversions ...