unity get input from keyboard and establish what key is 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: if get key down unity

using UnityEngine;
using System.Collections;

public class ExampleClass : MonoBehaviour
{
    void Update()
    {
        if (Input.GetKeyDown("space"))
        {
            print("space key was pressed");
        }
    }
}