In the C programming language, operators have a priority order that determines the order in which they are evaluated in an expression. Operators with a higher priority are evaluated before operators with a lower priority.

Here is the priority order of operators in C, from highest to lowest:

1. () (parentheses)
2. [] (array subscript)
3. -> (structure pointer)
4. . (structure member access)
5. ! (logical NOT)
6. ~ (bitwise NOT)
7. ++ (increment)
8. — (decrement)
9. • (unary minus)
10. • (dereference)
11. & (address-of)
12. sizeof
13. • (multiplication)
14. / (division)
15. % (modulo)
16. • (addition)
17. • (subtraction)
18. << (left shift)

19. (right shift)

20. < (less than)
21. <= (less than or equal to)

22. (greater than)

23. = (greater than or equal to)

24. == (equal to)
25. != (not equal to)
26. & (bitwise AND)
27. ^ (bitwise XOR)
28. | (bitwise OR)
29. && (logical AND)
30. || (logical OR)
31. ?: (conditional)
32. = (assignment)
33. += (add and assign)
34. -= (subtract and assign)
35. *= (multiply and assign)
36. /= (divide and assign)
37. %= (modulo and assign)
38. &= (bitwise AND and assign)
39. ^= (bitwise XOR and assign)
40. |= (bitwise OR and assign)
41. , (comma)

It is important to use parentheses appropriately when writing expressions in C to ensure that the operators are evaluated in the correct order. For example, in the following expression:

a + b * c

The multiplication (b * c) will be evaluated before the addition (a + …), because the multiplication operator has a higher priority than the addition operator. To change the order of evaluation, we can use parentheses:

(a + b) * c

In this case, the addition (a + b) will be evaluated before the multiplication (* c), because the parentheses have the highest priority and force the addition to be evaluated first.