How to read Shift + Click input?

Questions & Answers
1

I want to make a mouse input in which I use onmousedown and onmousedrag.
When I click, a boolean becomes true, and if it’s true an action will occur if I drag it.

I want to be able to change the action if I hold shift + left click + then drag.
How do I code it? Or how do I simply read Shift+Click input for Unity?

2

Just store the values of Input.Get... in variables, then combine those you need when you need them. And if it's for GUI stuff, check out the Event class.