How can i get a number input from a TextField? (Swift)(X-code) : i will get right to the question. 

Variable A = 0 
Variable B = 20

I want user to input number into TextField and i could save that number into variable A. Then i want to do an If statement where 

If A == B then (code) 

What i am having trouble is getting that number input from the textfield. 

Thanks in advance!