Stop at screen borders?

I'm trying to make my player stop at the screen border in a 2D game, but I can't because I "Cannot modify the return value of "Component.transform" because it is not a variable.

Code (CSharp):

1. if (Input.GetKey("down"))
2.         {
3.             transform.position -= ymov * Time.deltaTime;
4.             DirectionDown();
5.             if (transform.position.y < -4)
6.             {
7.                 transform.position.y = -4;
8.             }
9.         }

So I ended up trying to use a Vector3 to set the position, and it worked, except for the fact that the player moved to the center of the X-Axis because the Vector3 X value was set to 0. I tried putting in the transform.position.x as a value for the Vector3, but because it cannot reference a "Component.transform".

Code (CSharp):

1. public Vector3 vborder = new Vector3(transform.position.x, 4.5F, 0);

What do I do?

 

https://forum.unity.com/threads/help-stopping-player-from-moving-off-screen.86147/

 

I managed to make a solution. Since you couldn't add a non-static variable to a static variable, (or something like that), I just created the Vector3 variables in the Update method to make the variable non-static.

 

That's wonderful! Effective use of Vector3 variables - thanks for sharing!

 

Could you not also just use edge colliders at the borders? or is that more work?

 

ive heard that this can cause issues later on in development, and is generally kinda "hackjob". but im not absolutely sure why to be honest (pretty new to this)