Change the status of a variable when a button is pressed via interrupt routine.

[mdiro]

I am implementing an application when I need to set high a status variable when a button is pressed. I would like to do so via the interrupt routine of the push button. So, in gpio.c I have

void HAL_GPIO_EXTI_Callback(uint16_t GPIO_Pin){
    if (GPIO_Pin == GPIO_PIN_0){
    PB1_isPressed = 1;
    }
}

In the main.c I would like to have a statement like:

if (PB1_isPressed ==1){

do something

}

Now my questions are the following:

1. Is this a good practice?
2. where do I declare PB1_isPressed? and how?

Sorry for the very basic questions and thank you all for the help in advance :)

[Sarra.S]

Yes, I agree

the variable might be modified by the interrupt service routine so it must be declared as volatile

thank you for your comment