Symbols tells the compiler to perform specific mathematical or logical manipulations.

**Types of operators**

- Arithmetic
- Relational
- Logical
- Bitwise
- Assignment
- Misc

**Arithmetic**

Following table shows all the arithmetic operators supported by Objective-C language. Assume variable **A** holds 10 and variable **B** holds 20, then:

Operator | Description | Example |
---|---|---|

+ | Adds two operands | A + B will give 30 |

– | Subtracts second operand from the first | A – B will give -10 |

* | Multiplies both operands | A * B will give 200 |

/ | Divides numerator by denominator | B / A will give 2 |

% | Modulus Operator and remainder of after an integer division | B % A will give 0 |

++ | Increments operator increases integer value by one | A++ will give 11 |

— | Decrements operator decreases integer value by one | A– will give 9 |

Example of Arithmetic operators

**Relational**

Following table shows all the relational operators supported by Objective-C language. Assume variable **A** holds 10 and variable **B** holds 20, then

Operator | Description | Example |
---|---|---|

== | Checks if the values of two operands are equal or not, if yes then condition becomes true. | (A == B) is not true. |

!= | Checks if the values of two operands are equal or not, if values are not equal then condition becomes true. | (A != B) is true. |

> | Checks if the value of left operand is greater than the value of right operand, if yes then condition becomes true. | (A > B) is not true. |

< | Checks if the value of left operand is less than the value of right operand, if yes then condition becomes true. | (A < B) is true. |

>= | Checks if the value of left operand is greater than or equal to the value of right operand, if yes then condition becomes true. | (A >= B) is not true. |

<= | Checks if the value of left operand is less than or equal to the value of right operand, if yes then condition becomes true. | (A <= B) is true. |

**Note : later your will learn more about Relational operator with conditions**** **

**Logical **

Following table shows all the logical operators supported by Objective-C language. Assume variable **A** holds 1 and variable **B** holds 0, then:

Operator | Description | Example |
---|---|---|

&& | Called Logical AND operator. If both the operands are non-zero, then condition becomes true. | (A && B) is false. |

|| | Called Logical OR Operator. If any of the two operands is non-zero, then condition becomes true. | (A || B) is true. |

! | Called Logical NOT Operator. Use to reverses the logical state of its operand. If a condition is true, then Logical NOT operator will make false. | !(A && B) is true. |

**Note : later your will learn more about Logical operator with conditions**** **

**Bitwise**

Bitwise operator works on bits and perform bit by bit operation.

Assume if A = 60; and B = 13; now in binary format they will be as follows:

A = 0011 1100

B = 0000 1101

Operator | Description | Example |
---|---|---|

& | Binary AND Operator copies a bit to the result if it exists in both operands. | (A & B) will give 12, which is 0000 1100 |

| | Binary OR Operator copies a bit if it exists in either operand. | (A | B) will give 61, which is 0011 1101 |

^ | Binary XOR Operator copies the bit if it is set in one operand but not both. | (A ^ B) will give 49, which is 0011 0001 |

~ | Binary Ones Complement Operator is unary and has the effect of ‘flipping’ bits. | (~A ) will give -61, which is 1100 0011 in 2’s complement form. |

<< | Binary Left Shift Operator. The left operands value is moved left by the number of bits specified by the right operand. | A << 2 will give 240, which is 1111 0000 |

>> | Binary Right Shift Operator. The left operands value is moved right by the number of bits specified by the right operand. | A >> 2 will give 15, which is 0000 1111 |

### Assignment Operators

There are following assignment operators supported by Objective-C language:

Operator | Description | Example |
---|---|---|

= | Simple assignment operator, Assigns values from right side operands to left side operand | C = A + B will assign value of A + B into C |

+= | Add AND assignment operator, It adds right operand to the left operand and assigns the result to left operand | C += A is equivalent to C = C + A |

-= | Subtract AND assignment operator, It subtracts right operand from the left operand and assigns the result to left operand | C -= A is equivalent to C = C – A |

*= | Multiply AND assignment operator, It multiplies right operand with the left operand and assigns the result to left operand | C *= A is equivalent to C = C * A |

/= | Divide AND assignment operator, It divides left operand with the right operand and assigns the result to left operand | C /= A is equivalent to C = C / A |

%= | Modulus AND assignment operator, It takes modulus using two operands and assigns the result to left operand | C %= A is equivalent to C = C % A |

<<= | Left shift AND assignment operator | C <<= 2 is same as C = C << 2 |

>>= | Right shift AND assignment operator | C >>= 2 is same as C = C >> 2 |

&= | Bitwise AND assignment operator | C &= 2 is same as C = C & 2 |

^= | bitwise exclusive OR and assignment operator | C ^= 2 is same as C = C ^ 2 |

|= | bitwise inclusive OR and assignment operator | C |= 2 is same as C = C | 2 |

Example of Assignment Operators

**Misc Operators ↦ sizeof & ternary**

There are few other important operators including **sizeof** and **? :** supported by Objective-C Language.

Operator | Description | Example |
---|---|---|

sizeof() | Returns the size of an variable. | sizeof(a), where a is integer, will return 4. |

& | Returns the address of an variable. | &a; will give actual address of the variable. |

* | Pointer to a variable. | *a; will pointer to a variable. |

? : | Conditional Expression | If Condition is true ? Then value X : Otherwise value Y |

**Example of Misc Operators ↦ sizeof & ternary**

**Operators Precedence in Objective-C**

Operator precedence determines the grouping of terms in an expression

Certain operators have higher precedence than others; for example, the multiplication operator has higher precedence than the addition operator:

Category | Operator | Associativity |
---|---|---|

Postfix | () [] -> . ++ – – | Left to right |

Unary | + – ! ~ ++ – – (type)* & sizeof | Right to left |

Multiplicative | * / % | Left to right |

Additive | + – | Left to right |

Shift | << >> | Left to right |

Relational | < <= > >= | Left to right |

Equality | == != | Left to right |

Bitwise XOR | ^ | Left to right |

Bitwise OR | | | Left to right |

Logical AND | && | Left to right |

Logical OR | || | Left to right |

Conditional | ?: | Right to left |

Assignment | = += -= *= /= %=>>= <<= &= ^= |= | Right to left |

Comma | , | Left to right |

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