Input.GetKey
static function GetKey(name: string): bool;
static bool GetKey(string name);
static def GetKey(name as string) as bool
Description

Returns true while the user holds down the key identified by name. Think auto fire.

For the list of key identifiers see Input Manager. When dealing with input it is recommended to use Input.GetAxis and Input.GetButton instead since it allows end-users to configure the keys.
	function Update () {
		if (Input.GetKey ("up"))
			print ("up arrow key is held down");

if (Input.GetKey ("down")) print ("down arrow key is held down"); }
using UnityEngine;
using System.Collections;

public class Example : MonoBehaviour {
    void Update() {
        if (Input.GetKey("up"))
            print("up arrow key is held down");
        
        if (Input.GetKey("down"))
            print("down arrow key is held down");
        
    }
}
import UnityEngine
import System.Collections

public class Example(MonoBehaviour):

	def Update() as void:
		if Input.GetKey('up'):
			print('up arrow key is held down')
		if Input.GetKey('down'):
			print('down arrow key is held down')

static function GetKey(key: KeyCode): bool;
static bool GetKey(KeyCode key);
static def GetKey(key as KeyCode) as bool
Description

Returns true while the user holds down the key identified by the key KeyCode enum parameter.

	function Update () {
		if (Input.GetKey (KeyCode.UpArrow))
			print ("up arrow key is held down");

if (Input.GetKey (KeyCode.DownArrow)) print ("down arrow key is held down"); }
using UnityEngine;
using System.Collections;

public class Example : MonoBehaviour {
    void Update() {
        if (Input.GetKey(KeyCode.UpArrow))
            print("up arrow key is held down");
        
        if (Input.GetKey(KeyCode.DownArrow))
            print("down arrow key is held down");
        
    }
}
import UnityEngine
import System.Collections

public class Example(MonoBehaviour):

	def Update() as void:
		if Input.GetKey(KeyCode.UpArrow):
			print('up arrow key is held down')
		if Input.GetKey(KeyCode.DownArrow):
			print('down arrow key is held down')