unity if left key code example

Example 1: unity get key down

// KeyCode.Space : The key you press
// GetKeyDown : Is true once, when the key is pressed 
// If you want it to be true WHILE the key is pressed, try GetKey() instead
if(Input.GetKeyDown(KeyCode.Space))
{
	// Do something
}

Example 2: unity up arrow input

Input.GetKeyDown("up")