Union basics - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to declare a union named Data.

C

union [1] {
    int i;
    float f;
};

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AData

BStruct

CVar

DType

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'struct' instead of 'union' keyword.

Forgetting to name the union.

Using variable names instead of the union name.

The keyword union is followed by the union name. Here, Data is the correct union name.

2fill in blank

medium

Complete the code to access the integer member of the union variable d.

C

union Data d;
d.[1] = 10;

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Af

Bx

Ci

Dval

Attempts:

3 left

💡 Hint

Common Mistakes

Using the float member name instead of the integer one.

Using undefined member names.

To access the integer member of the union, use the member name i.

3fill in blank

hard

Fix the error in the union initialization.

C

union Data d = [1];

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A{3.14}

B{.i = 3}

C{.f = 3.14}

D{i = 3}

Attempts:

3 left

💡 Hint

Common Mistakes

Using assignment inside braces without dot notation.

Initializing with the wrong member name.

In C, to initialize a union member by name, use the designated initializer syntax like {.i = 3}.

4fill in blank

hard

Fill both blanks to create a union variable and assign a float value.

C

union Data [1];
[2].f = 5.5;

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Ad

Bdata

Cvalue

Dnum

Attempts:

3 left

💡 Hint

Common Mistakes

Using different names for declaration and access.

Using undefined variable names.

The variable name must be consistent. Here, d is used both to declare and access the union variable.

5fill in blank

hard

Fill all three blanks to create a union, declare a variable, and assign an integer value.

C

union [1] {
    int i;
    float f;
} [2];

[3].i = 42;

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

AData

Bd

Cvalue

Dnum

Attempts:

3 left

💡 Hint

Common Mistakes

Using different variable names in declaration and assignment.

Confusing union name with variable name.

The union is named Data, the variable declared is d, and we assign to d.i.