How to limit float variables ?

Questions & Answers
1

I want to limit my jumpPressure value within 10f, but as I multyply it by Time.deltatime*.3f, it gets higher every seconds.

Code below to have a look , thanks in advance

{
private Rigidbody2D playerRb;
public float jumpPressure = 0f;
private float intialJump = 80f;

void Start()
{
    playerRb = GetComponent<Rigidbody2D>();

}

void Update()
{   
    {
        if (Input.GetButton("Jump"))
        {
            {
                jumpPressure += Time.deltaTime * .3f;

// This is where the jumpPressure is getting too high every seconds and affecting my Addforce below//

            }
        }
        else
        {
            while (jumpPressure > 0)
            {
                jumpPressure = (Time.deltaTime * -7f);
            }
        }
    }

    playerRb.AddForce(Vector2.up * intialJump * jumpPressure, ForceMode2D.Force);
2

private Rigidbody2D playerRb;
public float jumpPressure = 0f;
private float intialJump = 80f;
private float jumpPressureLim = 10f;

 void Start()
 {
     playerRb = GetComponent<Rigidbody2D>();
 }
 void Update()
 {   
     {
         if (Input.GetButton("Jump") && jumpPressure <= jumpPressureLim)
         {
             {
                 jumpPressure += Time.deltaTime * .3f;  
             }
         }
         else
         {
             while (jumpPressure > 0)
             {
                 jumpPressure = (Time.deltaTime * -7f);
             }
         }
     }
     playerRb.AddForce(Vector2.up * intialJump * jumpPressure, ForceMode2D.Force);

}