IntelliJ Idea Shortcuts

Command	Description
`Alt`+`Shift`+`Ins`	Column selection. You can exit column selection mode by using `Esc` key. Column selection mode can be also used with keyboard only. When in column selection mode and holding `Shift`, you can extend cursor to the line above/bellow by using `↑` or `↓` keys.
`Shift`+`↑` or `Shift`+`↓`	Caret cloning. While holding `Shift`, you can press `↑` and `↓` arrows to clone cursor to the line above or bellow. You can exit caret cloning mode by using `Esc` key.
`Alt`+`Shift`	Multiple cursors. When holding `Alt` + `Shift`, clicking on a location creates a new cursor on that location in addition to all the already existing cursors. Unlike column selection, these cursors can be anywhere and don’t need to be vertically alignedYou can exit multiple cursors mode by using `Esc` key.
`Alt`+`Shift`	Multi-selection. This selection can be achieved by holding `Alt` + `Shift`. Then select the blocks by the mouse as usual. You can exit multi-selection mode by using `Esc` key.
`Shift`+`Ctrl`+`Alt`+`J`	Select all occurrences. Selects all the other occurrences in the current file of the already selected text. In case no text is selected, the closest word to the current cursor is selected. You can exit select all occurences mode by using `Esc` key.
`Alt`+`J`	Add occurrence. When you have a part of text selected, you can add the next occurrence of this string to your selection. You can exit add occurrence mode by using `Esc` key.
`Shift`+`Alt`+`J`	Remove occurrence. Removing the last occurrence from your selection. You can exit mode by using `Esc` key.