intellij-idea Useful Shortcuts Code Completion
Example
Basic code completion (the name of any class, method or variable)
Windows: Ctrl + Space
OS X / macOS: Cmd + Space
Smart code completion (filters the list of methods and variables by expected type)
Windows: Ctrl + Shift + Space
OS X / macOS: Cmd + Shift + Space
Overwriting code with a suggestion
Tab
Adding code from a completion suggestion
Enter
