Interrupting IF statement

Assume somewhere in the middle of the if statement, upon an input, I want to interrupt it.
How can I handle this ?

int check()
if(digitalRead(9) == LOW)
return 0;

this is the function and calling this function by writing down check(); statement whenever I want to check the condition to interrupt the if statement would work I think.
Don't have the board with me, so can't test. But this is my idea.

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