while hitting api it is not going to the code code example

Example 1: why does my if statement still run when the its not true c++

If the condition is true, result is set to 1, so much is true.
But in the other case, the content of result is undefined - 
so it can be anything,
even allowing the compiler to modify it at will as part of an 
optimization. 
You should either initialize result at its declaration,or add an else 
branch where you set it to the alternative value.

Example 2: what to do when you have a button in scene builder but it doesn't appear in yellow text in the controller?

Try to make sure that the fxml page is connected to the controller
Usually in the border pane line