Type coercion and conversion in Compiler Design - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to show implicit type coercion in an expression.

Compiler Design

result = 5 + [1]

Drag options to blanks, or click blank then click option'

ATrue

B10

C'10'

D"10"

Attempts:

3 left

💡 Hint

Common Mistakes

Using a number without quotes causes no coercion.

Using a boolean value changes the operation.

Adding an integer and a string causes implicit type coercion in some languages, converting the integer to a string and concatenating.

2fill in blank

medium

Complete the code to explicitly convert a string to an integer.

Compiler Design

number = [1]("123")

Drag options to blanks, or click blank then click option'

Astr

Bint

Cfloat

Dbool

Attempts:

3 left

💡 Hint

Common Mistakes

Using str() keeps it a string.

Using float() converts to decimal number.

The int() function converts a string representing a number into an integer explicitly.

3fill in blank

hard

Fix the error in the code to correctly convert a float string to a number.

Compiler Design

value = [1]("3.14")

Drag options to blanks, or click blank then click option'

Afloat

Bint

Cstr

Dbool

Attempts:

3 left

💡 Hint

Common Mistakes

Using int() causes a ValueError.

Using str() does not convert the type.

To convert a string with a decimal point to a number, use float(). Using int() causes an error.

4fill in blank

hard

Fill both blanks to create a dictionary comprehension that converts string numbers to integers only if they are greater than 10.

Compiler Design

result = {k: [1](v) for k, v in data.items() if [2](v) > 10}

Drag options to blanks, or click blank then click option'

Aint

Bfloat

Dlen

Attempts:

3 left

💡 Hint

Common Mistakes

Using float inconsistently.

Using len to compare numeric values.

The first blank converts the string value to an integer. The second blank converts the string to an integer to compare if it is greater than 10.

5fill in blank

hard

Fill all three blanks to create a dictionary comprehension that converts keys to uppercase strings, values to integers, and filters values greater than 5.

Compiler Design

result = { [1]: [2](v) for k, v in data.items() if [3](v) > 5 }

Drag options to blanks, or click blank then click option'

Ak.upper()

Bint

Dstr

Attempts:

3 left

💡 Hint

Common Mistakes

Using str() instead of int() for values.

Not converting keys to uppercase.

The keys are converted to uppercase strings using k.upper(). Values are converted to integers with int() for both conversion and comparison.

Practice

1. What is type coercion in compiler design?

easy

A. A process to optimize code execution speed

B. Manual conversion of one data type to another by the programmer

C. A syntax error caused by incompatible types

D. Automatic conversion of one data type to another by the system

Solution

1. Step 1: Understand the definition of type coercion

   Type coercion means the system automatically changes one data type to another without programmer intervention.

2. Step 2: Differentiate from type conversion

   Type conversion is manual, done by the programmer, unlike coercion which is automatic.

3. Final Answer:

   Automatic conversion of one data type to another by the system -> Option D

4. Quick Check:

   Type coercion = automatic conversion [OK]

Hint: Coercion is automatic, conversion is manual [OK]

Common Mistakes:

• Confusing coercion with manual conversion
• Thinking coercion causes errors
• Assuming coercion is optional

2. Which of the following is a correct example of explicit type conversion?

easy

A. int_value = int('123')

B. result = 5 + '5'

C. value = 10.5 + 2

D. x = 'hello' + 5

Solution

1. Step 1: Identify explicit type conversion syntax

   Explicit conversion uses functions like int(), float(), str() to manually change types.

2. Step 2: Check each option

   int_value = int('123') uses int('123') which converts string '123' to integer 123 explicitly.

3. Final Answer:

   int_value = int('123') -> Option A

4. Quick Check:

   Explicit conversion uses functions like int() [OK]

Hint: Look for functions like int(), float(), str() for explicit conversion [OK]

Common Mistakes:

• Confusing implicit coercion with explicit conversion
• Assuming adding string and number works without conversion
• Ignoring type conversion functions

3. What will be the output of this pseudo-code?

var a = '10';
var b = 5;
var c = a + b;

medium

A. 15

B. TypeError

C. '105'

D. '15'

Solution

1. Step 1: Identify types of variables

   Variable a is a string '10', b is a number 5.

2. Step 2: Understand type coercion in addition

   Adding string and number causes number to be coerced to string, so '10' + '5' = '105'.

3. Final Answer:

   '105' -> Option C

4. Quick Check:

   String + Number = String concatenation [OK]

Hint: Adding string + number converts number to string [OK]

Common Mistakes:

• Assuming numeric addition happens
• Expecting integer 15 as output
• Ignoring type coercion rules

4. Identify the error in this pseudo-code involving type coercion:

var x = '20';
var y = x - 5;
var z = y + '5';

medium

A. Error in adding number to string in last line

B. No error, all operations valid

C. Error in subtracting number from string

D. Error in variable declaration syntax

Solution

1. Step 1: Analyze subtraction operation

   Subtracting 5 from string '20' coerces '20' to number 20, so 20 - 5 = 15.

2. Step 2: Analyze addition operation

   Adding number 15 and string '5' coerces 15 to string '15', so '15' + '5' = '155'.

3. Final Answer:

   No error, all operations valid -> Option B

4. Quick Check:

   Subtraction coerces string to number, addition coerces number to string [OK]

Hint: Subtraction forces numeric coercion, addition may cause string coercion [OK]

Common Mistakes:

• Thinking subtraction with string causes error
• Assuming addition with string and number is invalid
• Confusing coercion direction

5. You have a list of mixed types: ["1", 2, "3", 4]. How can you convert all elements to integers using type coercion and conversion?

hard

A. Use a loop to apply explicit conversion function int() on each element

B. Add 0 to each element to force coercion to integer

C. Concatenate all elements as strings then convert to integer

D. Use a built-in function that automatically converts mixed lists

Solution

1. Step 1: Understand the list elements

   The list contains strings and integers mixed together.

2. Step 2: Apply explicit conversion

   Using a loop to apply int() on each element converts strings like '1' and '3' to integers 1 and 3, keeping integers unchanged.

3. Final Answer:

   Use a loop to apply explicit conversion function int() on each element -> Option A

4. Quick Check:

   Explicit conversion with int() on each element [OK]

Hint: Convert each element explicitly with int() in a loop [OK]

Common Mistakes:

• Assuming adding 0 coerces strings to integers
• Trying to convert entire list at once without loop
• Expecting automatic conversion of mixed lists