Unit 2

Question 1

Outline PHP’s variable conventions.

Answer 1

1. They start with a dollar sign
2. Variable type is not required when defining them
3. They must start with a letter or underscore
4. They cannot contain spaces
5. Variable names are case-sensitive

Question 2

Outline the conventions of a constant variable

Answer 2

1. They are case sensitive
2. Always uppercase
3. Starts with a letter or underscore
4. Automatically possess a global scope
5. They are created using define() function and const keyword

Question 3

What is the difference between const and define() in creating constant variables in PHP?

Answer 3

The keyword “const” defines constants at compile time, whereas the define() function defines constants at run time.

Question 4

What are the scalar data types in PHP?

Answer 4

bool, int, string, float

Question 5

What are the compound data types?

Answer 5

array, object, callable, iterable

Question 6

What are the special data types in PHP?

Answer 6

resource, NULL

Question 7

What are the three types of arrays in PHP?

Answer 7

1. Indexed array
2. Associative array
3. Multi-dimensional array

Question 8

What does the === operator do?

Answer 8

Returns true if both variables are equal and of the same type.

Question 9

What does the <> operator do?

Answer 9

Returns true if both variables are not equal.

Question 10

What does !== operator do?

Answer 10

Returns true if both operators are not equal or they are not of the same type

Question 11

What does <=> operator do?

Answer 11

Spaceship returns an integer less than, equal to, or greater than zero, depending on if the variable on the left is less than, equal to, or greater than the variable on the right.

Question 12

What does xor produce?

Answer 12

True if either variables is true, but not both

Question 13

What is the concatenation operator?

Answer 13

.