Objective-C Operators , Objective-C also provides a set of so called logical operators designed to return boolean true and false. The OR (||) operator returns 1 if one of its two operands evaluates to true, otherwise it returns 0
sizeof Operator
sizeof() returns the size of an variable. sizeof(anInteger) will return 4.
Conditional Expression
value = condition ? X:Y is called the Conditional Expression.
If Condition is true ? Then assign X to value, Otherwise assign Y to value.
Conditional operator ? : can be used to replace if...else statements. It has the following general form:
Exp1 ? Exp2 : Exp3;
Where Exp1, Exp2, and Exp3 are expressions. Notice the use and placement of the colon.
The value of a ? expression is determined like this: Exp1 is evaluated. If it is true, then Exp2 is evaluated and becomes the value of the entire ? expression. If Exp1 is false, then Exp3 is evaluated and its value becomes the value of the expression.
Address Operator
& returns the address of an variable. &a; will give actual address of the variable.
Pointer * operator
* is the Pointer operator to a variable. *a; will pointer to a variable.
Arithmetic Operators
Operator
Description
+
Adds two operands
–
Subtracts second operand from the first
*
Multiplies both operands
/
Divides numerator by denominator
%
Modulus Operator and remainder of after an integer division
++
Increment operator increases integer value by one
—
Decrement operator decreases integer value by one
Relational Operators
Operator
Description
==
Checks if the values of two operands are equal or not.
!=
Checks if the values of two operands are not equal.
>
Checks if the value of left operand is greater than the value of right operand.
<
Checks if the value of left operand is less than the value of right operand.
>=
Checks if the value of left operand is greater than or equal to the value of right operand.
<=
Checks if the value of left operand is less than or equal to the value of right operand.
Logical Operators
Operator
Description
&&
Logical AND operator. If both the operands are non zero then condition becomes true.
||
Logical OR Operator. If any of the two operands is non zero then condition becomes true.
!
Logical NOT Operator. Reverse the logical state of its operand. If a condition is true, then Logical NOT operator will make false.
Bitwise Operators
Operator
Description
&
Binary AND Operator copies a bit to the result if it exists in both operands.
|
Binary OR Operator copies a bit if it exists in either operand.
^
Binary XOR Operator copies the bit if it is set in one operand but not both.
~
Binary Ones Complement Operator is unary and has the effect of ‘flipping’ bits.
<<
Binary Left Shift Operator. The left operands value is moved left by the number of bits specified by the right operand.
>>
Binary Right Shift Operator. The left operands value is moved right by the number of bits specified by the right operand.
p
q
p & q
p | q
p ^ q
0
0
0
0
0
0
1
0
1
1
1
1
1
1
0
1
0
0
1
1
Assignment Operators
=
Assignment operator, Assigns values from right side operands to left side operand
+=
Add AND assignment operator, It adds right operand to the left operand and assigns the result to left operand
-=
Subtract AND assignment operator, It subtracts right operand from the left operand and assigns the result to left operand
*=
Multiply AND assignment operator, It multiplies right operand with the left operand and assigns the result to left operand
/=
Divide AND assignment operator, It divides left operand with the right operand and assigns the result to left operand
%=
Modulus AND assignment operator, It takes modulus using two operands and assigns the result to left operand
<<=
Left shift AND assignment operator
>>=
Right shift AND assignment operator
&=
Bitwise AND assignment operator
^=
bitwise exclusive OR and assignment operator
|=
bitwise inclusive OR and assignment operator
Compound Assignment Operators
Operator
Description
x += y
Add x to y and place result in x
x -= y
Subtract y from x and place result in x
x *= y
Multiply x by y and place result in x
x /= y
Divide x by y and place result in x
x %= y
Perform Modulo on x and y and place result in x
x &= y
Assign to x the result of logical AND operation on x and y
x |= y
Assign to x the result of logical OR operation on x and y
x ^= y
Assign to x the result of logical Exclusive OR on x and y
Increment and Decrement Operators
x = x + 1; // Increase value of variable x by 1
x = x - 1; // Decrease value of variable x by 1
x++; Increment x by 1
x--; Decrement x by 1
Comparison Operators
if (x == y)
// Perform task
Boolean Logical Operators
bool flag = true; //variable is true
bool secondFlag;
secondFlag = !flag; // secondFlag set to false
if ((10 < 20) || (20 < 10))
NSLog (@"Expression is true");
if ((10 < 20) && (20 < 10))
NSLog (@"Expression is true");
The Ternary Operator
[condition] ? [true expression] : [false expression]
int x = 10;
int y = 20;
NSLog(@"Largest number is %i", x > y ? x : y );
