unity call function only once in update code example

Example: unity call function on update once per second

float elapsedTime;
float timeLimit = 0.1f;

private void Update()
{
    elapsedTime += Time.deltaTime;
    if (elapsedTime >= timeLimit)
    {
        elapsedTime = 0;
        //Rest of your code or function call goes here
    }
}