Some PHP Exercises

What does an echo function do?
What is the difference between using single quotes and double quotes in the echo function?

The echo function

The echo function is used to print one or more variable in the output.
Syntax: echo variable-name;

Example inputs

1.
echo “smith”;
2.
$name = “Jones”;
echo $name;
3.
$name=”Natasha”;
echo “My name is $name”;
echo “
”
echo “What is yours?”;
4.
$name = “Robin”;
echo ‘My name is $name’
5.
echo ‘My’,’name’,’is’,’John’;

Example outputs:

1.
Smith
2.
Jones
3.
My name is Natasha
What is yours?
4.
My name is $name
5.
My name is John

Some PHP Exercises

What is the assignment operator in PHP?
What are the rules for naming a PHP variable?
Can I start a PHP variable name with the # symbol?
Should we always declare a variable in PHP specifying its data type?
Is it true that all statements in PHP should end with a comma?

Variables in PHP

Variables are identifiers to the memory location to store data. A PHP program can contain as many variables as you’d want.
Variable names in PHP begin with a dollar sign "$" and the values are assigned using the “=” operator.
Following the $ sign should be an alphabet or an underscore.
A variable name can contain any number of alphabets, numbers or underscores.
A PHP variable name cannot contain special characters like *, +, @, # etc.
In PHP we need not specify the variable type, as PHP takes the data type of the assigned value.

1. $1name is an invalid variable name as it starts with a number.
2. $_name or $name1 are, however, valid PHP variable names.
3.
$Name = "David";
$Age = 16;
In the above case, we assign values to the variable without mentioning their type. PHP automatically recognizes $Age as a numeric variable and $Name as a string.