Precedence And Associativity Of Operators
Precedence of operators
If more than one operators are involved in an expression then, C language has predefined rule of priority of operators. This rule of priority of operators is called operator precedence.
In C, precedence of arithmetic operators(*,%,/,+,-) is higher than relational operators(==,!=,>,<,>=,<=) and precedence of relational operator is higher than logical operators(&&, || and !). Suppose an expression:
(a>b+c&&d) This expression is equivalent to: ((a>(b+c))&&d) i.e, (b+c) executes first then, (a>(b+c)) executes then, (a>(b+c))&&d) executes
Associativity of operators
Associativity indicates in which order two operators of same precedence(priority) executes. Let us suppose an expression:
a==b!=c
Here, operators == and != have same precedence. The associativity of both == and != is left to right, i.e, the expression in left is executed first and execution take pale towards right. Thus, a==b!=c equivalent to :
(a==b)!=c
The table below shows all the operators in C with precedence and associativity.
Note: Precedence of operators decreases from top to bottom in the given table.
| Operator | Meaning of operator | Associativity |
|---|---|---|
| () [] -> . |
Functional call Array element reference Indirect member selection Direct member selection |
Left to right |
| ! ~ + - ++ -- & * sizeof (type) |
Logical negation Bitwise(1 's) complement Unary plus Unary minus Increment Decrement Dereference Operator(Address) Pointer reference Returns the size of an object Type cast(conversion) |
Right to left |
| * / % |
Multiply Divide Remainder |
Left to right |
| + - |
Binary plus(Addition) Binary minus(subtraction) |
Left to right |
| << >> |
Left shift Right shift |
Left to right |
| < <= > >= |
Less than Less than or equal Greater than Greater than or equal |
Left to right |
| == != |
Equal to Not equal to |
Left to right |
| & | Bitwise AND | Left to right |
| ^ | Bitwise exclusive OR | Left to right |
| | | Bitwise OR | Left to right |
| && | Logical AND | Left to right |
| || | Logical OR | Left to right |
| ?: | Conditional Operator | Left to right |
| = *= /= %= -= &= ^= |= <<= >>= |
Simple assignment Assign product Assign quotient Assign remainder Assign sum Assign difference Assign bitwise AND Assign bitwise XOR Assign bitwise OR Assign left shift Assign right shift |
Right to left |
| , | Separator of expressions | Left to right |
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