Gettype and typeof checks in PHP - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ Predict Output

intermediate

What is the output of gettype() for a float?

Consider the following PHP code:

$value = 3.14;
echo gettype($value);

What will be printed?

PHP

$value = 3.14;
echo gettype($value);

A "double"

B "float"

C "decimal"

D "real"

💡 Hint

PHP uses a specific string for floating point numbers in gettype().

In PHP 7.2 and later, gettype() returns "float" for floating point numbers, not "double" or other variants.

❓ Predict Output

intermediate

What does gettype() return for a boolean false?

Given this PHP code:

$flag = false;
echo gettype($flag);

What is the output?

PHP

$flag = false;
echo gettype($flag);

A "bool"

B "false"

C "boolean"

D "bit"

💡 Hint

PHP uses a full word for boolean types in gettype().

gettype() returns "boolean" for both true and false values in PHP.

❓ Predict Output

advanced

What is the output of this gettype check in PHP?

Analyze this PHP snippet:

$var = 42;
if (gettype($var) === 'integer') {
    echo 'Integer!';
} else {
    echo 'Not integer';
}

What will be printed?

PHP

$var = 42;
if (gettype($var) === 'integer') {
    echo 'Integer!';
} else {
    echo 'Not integer';
}

A Integer!

B Syntax error

C Not integer

D Runtime error

💡 Hint

Check the exact string returned by gettype() for integers.

gettype() returns "integer" for integer values. The strict comparison === 'integer' matches, so 'Integer!' is printed.

❓ Predict Output

advanced

What error does this typeof check cause?

Look at this PHP code:

$value = 'hello';
if (typeof($value) === 'string') {
    echo 'It is a string';
} else {
    echo 'Not a string';
}

What happens when this code runs?

PHP

$value = 'hello';
if (typeof($value) === 'string') {
    echo 'It is a string';
} else {
    echo 'Not a string';
}

A Warning: Invalid argument

B Not a string

C It is a string

D Fatal error: undefined function typeof()

💡 Hint

Check if typeof() is a valid PHP function.

PHP does not have a typeof() function. Using it causes a fatal error about undefined function.

🧠 Conceptual

expert

Which statement about gettype() in PHP is TRUE?

Select the correct statement about the behavior of gettype() in PHP.

A gettype() returns 'boolean' for both true and false values.

B gettype() returns 'string' for null values.

C gettype() returns 'float' for floating point numbers.

D gettype() returns 'int' for integer values.

💡 Hint

Recall the exact strings gettype() returns for different types.

gettype() returns 'boolean' for true and false, 'integer' for integers, 'float' for floats, and 'NULL' for null values.