In computer programming, the term variable scope usually refers to the part of the code where the variable can be used (e.g. a function, a loop or the whole program).
In C/C++ there are the following scopes:
- Block scope – a variable defined inside a function has a block scope and is accessible from the place of definition until the end of the block where it is defined. In C++, blocks are delimited with curly brackets
- Function scope – function parameters have a function scope and can be used anywhere inside the function.
- File scope – defined outside functions, these variables are visible from the place of definition until the end of the file.
- Global scope – similar to file scope, but these variables are visible in all the functions in the program.