The document discusses type conversion in C programming, covering both implicit and explicit type conversions. It explains how C automatically converts types during operations and demonstrates explicit type casting by the programmer. Additionally, it details operator precedence and associativity rules that dictate the order of operations in expressions.

1. Type Conversion
Precedence & Associativity
- Aakash Singh
C
Learners

2. Type Conversion
 What is Type Conversion?
• Type Casting or Type Conversion is a way to
convert a variable from one data type to another
data type.
• For example, if you want to store a long value
into a simple integer then you can type cast long
to int.
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3. Type Conversion
 Types of Type Conversion
• There are two types of type conversion –
1. Implicit Type Conversion
2. Explicit Type Conversion
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4. 1. Implicit Type Conversion
 What is Implicit Type Conversion?
• C automatically converts any intermediate values
to the proper type so that the expression can be
evaluated without losing any significance.
• This automatic conversion is known implicit type
conversion.
• If the operands are of different types, the ‘lower
type’ is automatically converted to the ‘higher’
type before the operation proceeds.
• The result is of the higher type.
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5. Implicit Type Conversion
short char
int
Unsigned int
long int
Unsigned long int
float
double
long double
Conversion
Hierarchy
C uses rule that, in all expressions except assignments, any implicit type
conversions are made from a lower size to a higher size type as shown
below.
This hierarchy
can be used
while evaluating
expressions.
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6. Example of Implicit Type Conversion
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7. Example of Implicit Type Conversion
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8. 1. Explicit Type Conversion
 What is Explicit Type Conversion?
• The type conversion performed by the
programmer by posing the data type of the
expression of specific type is known as explicit
type conversion.
• The general form of a cast is :
(type-name) expression
• Here, ‘type-name’ is one of the standard C data
types and the expression may be a constant,
variable, or an expression.
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9. Use of Explicit Type Casting
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Example Action
X=(int)7.5
7.5 is converted to integer by
truncation.
a = (int)21.3/(int)4.5
Evaluated as (21/4) and the result
would be 5.
b = (double)sum/n Division is done in floating point mode.
y = (int)(a+b)
The result of (a+b) is converted to
integer.
z = (int)a+b
a is converted to integer and then
added to b.
p = cos((double)x) Converts x to double before using it.

10. Example of Explicit Type Conversion
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11. Example of Explicit Type Conversion
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12. Precedence & Associativity
 What is Precedence?
• C has a precedence associated with it. This
precedence is used to determine how an expression
involving more than one operator is evaluated.
 What is Associativity?
• The operators at higher level of precedence are
evaluated first.
• The operators of the same precedence are evaluated
either from ‘left to right’ or from ‘right to left’
depending on the level. This is known as the
associativity property of an operator.
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13. Precedence & Associativity
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 Precedence rules decides the order in which
different operators are applied.
 Associativity rule decides the order in which
multiple occurrences of the same level operator
are applied.
 C Operators with their Precedence & Associativity
are listed in the following table.

14. 14
Operator Description Associativity Rank
()
[]
Function call
Array element
reference
Left to right 1
+
-
++
--
!
~
*
&
sizeof
(type)
Unary plus
Unary minus
Increment
Decrement
Logical Negation
Ones complement
Pointer reference
Address
Size of an object
Type cast
Right to left 2
*
/
%
Multiplication
Division
Modulus
Left to right 3
+
-
Addition
Subtraction
Left to right 4
<<
>>
Left shift
Right shift
Left to right 5

15. 15
Operator Description Associativity Rank
<
<=
>
>=
Less than
Less than or equal to
Greater than
Greater than or equal
to
Left to right 6
==
!=
Equality
Inequality
Left to right 7
& Bitwise AND Left to right 8
^ Bitwise XOR Left to right 9
| Bitwise OR Left to right 10
&& Logical AND Left to right 11
|| Logical OR Left to right 12
?: Conditional expression Right to left 13

16. 16
Operator Description Associativity Rank
=
*= /= %=
+= -= &=
^= |=
<<= >>=
Assignment
operators
Right to left 14
, Comma operator Left to right 15

17. Summary of operator precedence
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 ‘Comma’ operator has lowest precedence.
 ‘Unary Operators’ are operators having highest
precedence.
 Operators sharing common block in the above
table have equal priority or precedence.
 While solving expression, equal priority operators
are handled on the basis of FIFO [First in First Out]
i.e., Operator Coming First is handled First.

18. Example of Precedence
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19. Example of Associativity
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