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iOS Objective-C Basics (Retired) Fundamentals of C Operators and Expressions

Posted by David kalem
David kalem
194 Points

Further explanation needed

i dont understand this :&

2 Answers

Oliver Ni
Oliver Ni
7,284 Points
Oliver Ni
Oliver Ni
7,284 Points

& is binary AND, and it returns 1 if both numbers are 1, and otherwise 0.

Here's an example:

5 & 3

5 in binary = 0101

3 in binary = 0011

0101

0011

?

0001

so 5 & 3 = 1

James Andrews
James Andrews
7,245 Points
James Andrews
James Andrews
7,245 Points

You should provide more information in context to what you don't understand. & is used in many ways in C and C++ and Objective-C you can do X & Y or Y && Y or eve &x or &y. Just to give you some examples.

X & Y the & us being used a sa bitwise operator to shift bits (which I believe this course doesn't talk about but you should know it exists).

if ( X && Y) { .... } means if X is true and Y is true then do whatever's in the code block.

&x or &y are part of pointers and are used to point to the memory address of a given pointer.

int myInt = 100 int *myPointerInt = &myInt;

What it means is that myPointerInt points to the same memory space as myInt. if I do this.

myInt = 110

because I am changing the value of myInt the value of myPointerInt would also change because myPointerInt points to the data that is allocated by myInt.