CLion
 
2022.3
Shortcuts: Windows
Get CLion
You are viewing the documentation for an earlier version of CLion.
  1. Work with source code
  2. Refactoring
  3. Extract
  4. Extract function

Extract function

Last modified: 28 September 2022

The following demo illustrates the usage of the Extract function refactoring, as well as Extract parameter, Extract lambda parameter, and Live templates:

When the Extract Function refactoring is invoked, CLion analyses the selected block of code and detects variables that are the input for the selected code fragment and the variables that are output for it.

The detected output variable is used as a return value for the extracted function.

C++ Example

Before

After

int main() {
    int x = 15;
    int y = 10;

    int z = x - y;

    return 0;
}
int main() {
    int x = 10;
    int y = 15;

    int z = XSubY(x,y);

    return 0;
}

void XSubY(int x, int y) { return x - y; }

Extract a function

  1. In the editor, select a block of code to be transformed into a function.

    tip

    The code fragment to form the method does not necessarily have to be a set of statements. It may also be an expression used somewhere in the code.

  2. From the main menu or from the context menu of the selection, choose Refactor | Extract | Method or press Ctrl+Alt+M.

  3. In the Extract Function dialog that opens, specify the name of the new function.

  4. Specify the return type of the function.

  5. If the function has not been yet declared, select declaration place: above or below current place.

  6. In the parameters pane:

    • Add the new parameters or delete the unnecessary ones

    • Rename parameters or/and change their types by clicking the corresponding parameter lines and entering the new names and types

    • Reorder parameters in the list

    • Change the return type of the function

  7. Check the result in the Signature Preview pane and click Extract to create the function.

    The selected code fragment will be replaced with a function call.

    Extract method dialog

See also

Procedures

Reference

External Links