if (input.getkeydown(keycode.space)) code example

Example 1: 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");
        }
    }
}

Example 2: press key run code unity c#

if(Input.GetKey(KeyCode.space))
	{
  		print("Space key was pressed")
	}