2 2. operators
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The document discusses operator precedence and associativity in C. It covers comparison, arithmetic, assignment, increment/decrement, bitwise, and logical operators. For each operator, it provides the symbol, description, examples, and order of precedence from highest to lowest. It also gives examples of how to use various operators in code snippets.
![Precedence and Associativity of Operators
Operators Associativity
( ) [ ] . -> ++(postfix) --(postfix) left to right
++(prefix) --(prefix) ! ~ sizeof(type)
right to left
+(unary) -(unary) &(address) *(dereference)
* / % left to right
+ - left to right
<< >> left to right
< <= > >= left to right
== != left to right
& left to right
^ left to right
| left to right
&& left to right
|| left to right
? : right to left
= += -= *= /= %= >>= <<= &= ^= |= right to left
2](https://image.slidesharecdn.com/2-2-operators-130311003649-phpapp01/85/2-2-operators-2-320.jpg)
![Increment and Decrement Operators
[Ex] int i = 4, j;
j = ++i + 3;
printf(“i : %d, j = %dn”, i, j);
j = i++ + 3;
printf(“i : %d, j = %dn”, i, j);
j = --i + 3;
printf(“i : %d, j = %dn”, i, j);
j = i-- + 3;
printf(“i : %d, j = %dn”, i, j);
i = 5, j =8
i = 6, j =8
i = 5, j =8
i = 4, j =8
7](https://image.slidesharecdn.com/2-2-operators-130311003649-phpapp01/85/2-2-operators-7-320.jpg)
![Example
[Ex]
i = 3 , j = 2 , k = 1 ;
if ( i > j > k ) printf( “Yes” )
else printf( “No” ) ;
[Ex]
int a, i =1, j = 2, k ;
a = i < 2 + j;
j = 5 * (k = 3);
printf( “%d %d %dn”, a, i, j, k ) ;
( i < j ) && ( j < k )
This statement means that j is between i and k.
11](https://image.slidesharecdn.com/2-2-operators-130311003649-phpapp01/85/2-2-operators-11-320.jpg)
![Assignment Operators
Compound Assignment
– Compound Assignment operators
op= [Ex] *=, -=, /=, %=, +=
– variable = variable op (expression)
=> variable op= expression
[Ex] int k = 5;
k += 2; /* k = k + 2, k=7 */
k -= 2; /* k = k - 2, k=5 */
k *= 2; /* k = k * 2, k=10 */
k /= 2; /* k = k / 2, k=5 */
k %= 2; /* k = k % 2, k=1 */
13](https://image.slidesharecdn.com/2-2-operators-130311003649-phpapp01/85/2-2-operators-13-320.jpg)
2 2. operators
- 1. Operators
- 2. Precedence and Associativity of Operators Operators Associativity ( ) [ ] . -> ++(postfix) --(postfix) left to right ++(prefix) --(prefix) ! ~ sizeof(type) right to left +(unary) -(unary) &(address) *(dereference) * / % left to right + - left to right << >> left to right < <= > >= left to right == != left to right & left to right ^ left to right | left to right && left to right || left to right ? : right to left = += -= *= /= %= >>= <<= &= ^= |= right to left 2
- 3. Operators Comparison: C operator Description Example == = a == 2 != Not equal a != 3 < < a<3 > > a>4 <= a <= 5 >= a >= 3 ! Negative !(a < 3) && and (3 < a) && (a < 5) || or (a < 3) || ( 5 < a) 3
- 4. Operators Arithmetic Operator Description Example + + a+2 – – a–3 * * (Mutiplication) a*3 / / (Division) a/4 % Remainder a%5 ++ Increment a++, ++a == Decrement a--, --a 4
- 5. Operators Assignment Operator Description Example = assignment a=b += a=a+3 a += 3 -= a=a-3 a -= 3 *= a=a*3 a *= 3 /= a=a/3 a /= 3 %= a=a%3 a %= 3 5
- 6. Increment and Decrement Operators Increment operator Postfix k++ k = k - 1 ; Prefix ++k Decrement operator Postfix k-- k = k - 1 ; Prefix --k But, It is a different when use with another operator Prefix : increase or decrease before used in expression Postfix : increase or decrease after used in expression 6
- 7. Increment and Decrement Operators [Ex] int i = 4, j; j = ++i + 3; printf(“i : %d, j = %dn”, i, j); j = i++ + 3; printf(“i : %d, j = %dn”, i, j); j = --i + 3; printf(“i : %d, j = %dn”, i, j); j = i-- + 3; printf(“i : %d, j = %dn”, i, j); i = 5, j =8 i = 6, j =8 i = 5, j =8 i = 4, j =8 7
- 8. Bit Operators <<, >>, |, &, ^,~ – << : Left shift n places a = 100 << 1 ; 100 -> 01100100 printf( “%d”, a ) Shift to left by 1 bit 11001000 (=200) – >> : Right shift n places a = 100 >> 1 ; 100 -> 01100100 printf( “%d”, a ) Shift to right by 1 bit 001100100 (=50) 8
- 9. Bit Operators (8bit Computer) <<, >>, |, &, ^,~ – | : Logical OR, if either bit is 1, 100 -> 01100100 the result is 1 200 -> 11001000 a = 100 | 200 ; ------------------- printf( “%d”, a ) a = 11101100 (236) – & : Logical AND, if both bits are 1, 100 -> 01100100 the result is 1 200 -> 11001000 a = 100 & 200 ; ------------------- printf( “%d”, a ) a = 01000000 (64) – ^ : Logical XOR, if one and only one bit is 1, the result is 1 100 -> 01100100 a = 100 ^ 200 ; 200 -> 11001000 printf( “%d”, a ) ------------------- a = 10101100 (172) 9
- 10. Bit Operators (8bit Computer) <<, >>, |, &, ^,~ – ~ : Logical inverter 100 -> 01100100 ------------------- a = ~100; a = 10011011 (155) printf( “%d”, a ) 10
- 11. Example [Ex] i = 3 , j = 2 , k = 1 ; if ( i > j > k ) printf( “Yes” ) else printf( “No” ) ; [Ex] int a, i =1, j = 2, k ; a = i < 2 + j; j = 5 * (k = 3); printf( “%d %d %dn”, a, i, j, k ) ; ( i < j ) && ( j < k ) This statement means that j is between i and k. 11
- 12. Example Example int a = 5, b = 6, c = 7 ; int d ; printf( “%d %d %dn, a < b, a > b, a != b ) ; d = (a < b) && (b < c ) ; printf( “%d %d %dn”, d, (a > b) || (b > c), !(!5) ) ; 12
- 13. Assignment Operators Compound Assignment – Compound Assignment operators op= [Ex] *=, -=, /=, %=, += – variable = variable op (expression) => variable op= expression [Ex] int k = 5; k += 2; /* k = k + 2, k=7 */ k -= 2; /* k = k - 2, k=5 */ k *= 2; /* k = k * 2, k=10 */ k /= 2; /* k = k / 2, k=5 */ k %= 2; /* k = k % 2, k=1 */ 13