1 / 36

Objectives

Learn about the categories of expressions, rules of precedence and associativity, side effects, type conversions, and statement types in C programming. Understand postfix and prefix expressions, unary and binary expressions, and compound assignments.

agulley
Download Presentation

Objectives

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Chapter 3 Structure of a C Program Objectives ❏ To be able to list and describe the six expression categories ❏ To understand the rules of precedence and associativity in evaluating expressions ❏ To understand the result of side effects in expression evaluation ❏ To be able to predict the results when an expression is evaluated ❏ To understand implicit and explicit type conversion ❏ To understand and use the first four statement types: null, expression, return, and compound Computer Science: A Structured Programming Approach Using C

  2. 3-1 Expressions An expression is a sequence of operands and operators that reduces to a single value. Expressions can be simple or complex. An operator is a syntactical token that requires an action be taken. An operand is an object on which an operation is performed; it receives an operator’s action. Topics discussed in this section: Primary Expressions Postfix Expressions Prefix Expressions Unary Expressions Binary Expressions Computer Science: A Structured Programming Approach Using C

  3. Note An expression always reduces to a single value. Computer Science: A Structured Programming Approach Using C

  4. FIGURE 3-2 Postfix Expressions Computer Science: A Structured Programming Approach Using C

  5. Note (a++) has the same effect as (a = a + 1) Computer Science: A Structured Programming Approach Using C

  6. FIGURE 3-3 Result of Postfix a++ Computer Science: A Structured Programming Approach Using C

  7. Note The operand in a postfix expression must be a variable. Computer Science: A Structured Programming Approach Using C

  8. PROGRAM 3-1 Demonstrate Postfix Increment Computer Science: A Structured Programming Approach Using C

  9. PROGRAM 3-1 Demonstrate Postfix Increment (continued) Computer Science: A Structured Programming Approach Using C

  10. FIGURE 3-4 Prefix Expression Computer Science: A Structured Programming Approach Using C

  11. Note The operand of a prefix expression must be a variable. Computer Science: A Structured Programming Approach Using C

  12. FIGURE 3-5 Result of Prefix ++a Computer Science: A Structured Programming Approach Using C

  13. Note (++a) has the same effect as (a = a + 1) Computer Science: A Structured Programming Approach Using C

  14. PROGRAM 3-2 Demonstrate Prefix Increment Computer Science: A Structured Programming Approach Using C

  15. PROGRAM 3-2 Demonstrate Prefix Increment (continued) Computer Science: A Structured Programming Approach Using C

  16. Note If ++ is after the operand, as in a++, the increment takes place after the expression is evaluated. If ++ is before the operand, as in ++a, the increment takes place before the expression is evaluated. Computer Science: A Structured Programming Approach Using C

  17. FIGURE 3-6 Unary Expressions Computer Science: A Structured Programming Approach Using C

  18. Table 3-1 Examples of Unary Plus And Minus Expressions Computer Science: A Structured Programming Approach Using C

  19. FIGURE 3-7 Binary Expressions Computer Science: A Structured Programming Approach Using C

  20. Note Both operands of the modulo operator (%) must be integral types. Computer Science: A Structured Programming Approach Using C

  21. PROGRAM 3-3 Binary Expressions Computer Science: A Structured Programming Approach Using C

  22. PROGRAM 3-3 Binary Expressions (continued) Computer Science: A Structured Programming Approach Using C

  23. PROGRAM 3-3 Binary Expressions (continued) Computer Science: A Structured Programming Approach Using C

  24. Note The left operand in an assignment expression must be a single variable. Computer Science: A Structured Programming Approach Using C

  25. Table 3-2 Expansion of Compound Expressions Computer Science: A Structured Programming Approach Using C

  26. PROGRAM 3-4 Demonstration of Compound Assignments Computer Science: A Structured Programming Approach Using C

  27. PROGRAM 3-4 Demonstration of Compound Assignments Computer Science: A Structured Programming Approach Using C

  28. PROGRAM 3-4 Demonstration of Compound Assignments Computer Science: A Structured Programming Approach Using C

  29. 3-2 Precedence and Associativity Precedence is used to determine the order in which different operators in a complex expression are evaluated. Associativity is used to determine the order in which operators with the same precedence are evaluated in a complex expression. Topics discussed in this section: Precedence Associativity Computer Science: A Structured Programming Approach Using C

  30. PROGRAM 3-5 Precedence Computer Science: A Structured Programming Approach Using C

  31. PROGRAM 3-5 Precedence Computer Science: A Structured Programming Approach Using C

  32. Computer Science: A Structured Programming Approach Using C

  33. FIGURE 3-8 Left-to-Right Associativity Computer Science: A Structured Programming Approach Using C

  34. FIGURE 3-9 Right-to-Left Associativity Computer Science: A Structured Programming Approach Using C

  35. So you can have things like:int i =1;int j =2;i = j*= 2; // i = j = 4 afteri += i + j+=2; // j=6, i = 10 // after Computer Science: A Structured Programming Approach Using C

  36. You can actually sayint i, sum;i = sum = 3 +1; // Right to left // associativityAnd i will equal 4, but it is not good programming practice. Computer Science: A Structured Programming Approach Using C

More Related