Media Studies Chapter 10 Homework Write Statement The Following Both Variables And

Suggested answers for an accompanying worksheet for the book: Digital Media Primer, Yue–Ling

Worksheet: Syntax Review and Code Writing Exercises for Part 2 of

Chapter 10

Objectives:

• Review the syntax by writing general syntax and example code for:

o if statements

o switch statements

o function definitions

o invoking functions

o functions that return a value

o parameters and arguments

• The completed worksheet can be used as a quick reference for programming labs and

studying for tests and exams.

Syntax Review:

if statement

General Syntax:

Example:

if/else statement

General Syntax:

Example:

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if/else if statement

General Syntax:

Example:

if (score > 90)

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switch statement

General Syntax:

switch ( expression )

Example:

switch (score)

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Function Definitions and Function Calls

What are functions and function definitions?

What are function calls?

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Function Definitions

General Syntax:

Example:

Invoking a Function

General Syntax:

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Function definition

for a function that returns a value

General Syntax:

Invoking a function that returns a value

General Syntax:

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Write a function definition

for a function that takes parameters

General Syntax:

Invoking a function that takes parameters

General Syntax:

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Write a function definition

for a function that returns a value and takes parameters

General Syntax:

Example:

Invoking a function that returns a value and takes parameters

General Syntax:

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Code Writing Exercises:

1. Write a function definition to calculate the sum of two variables.

Then, make a function call (i.e. invoke the function.)

2. Write a function definition to calculate the sum of two variables, and return the sum.

Then, make a function call (i.e. invoke the function.)

3. Write an if statement to do the following.

4. Write an if statement to do the following.

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5. What will the value of x be after the following statements are executed?

(a)

var n = 6;

(b)

var n = 6;

(c)

var n = 6;

(d)

var n = 6;

(e)

var n = 6;

var score = 51;

(f)

var n = 6;

var score = 51;

(g)

var n = 6;

var score = 51;

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6. Write a switch–statement that does the same as the following if-statement. Assume the

variable reaction has been declared. You don’t need to declare the variable reaction.

if (reaction == 0)

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7. Write a function definition (that takes three parameters). One parameter is used as the sales

price, one parameter as the discount, and one parameter as the tax rate. The function is to

calculate the total sales after taking discount off the sales price, and added with tax.

(You can make up a reasonable formula to calculate the total. The purpose of this question

is for you to practice writing a function with parameters; it’s not about actual accounting.)

Then, make a function call (i.e. invoke the function.)

8. Write a function definition that does the same task as the previous question but it also

returns the value of the result.

Then, make a function call (i.e. invoke the function.)

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