A variable starts with the $ sign, followed by the name of the variable
A variable name must start with a letter or the underscore character
A variable name cannot start with a number
A variable name can only contain alpha-numeric characters and underscores (A-z, 0-9, and _ )
Variable names are case-sensitive ($age and $AGE are two different variables)
Exercises
DeclareAnInt
An integer must have at least one digit
An integer must not have a decimal point
An integer can be either positive or negative
Integers can be specified in: decimal (base 10), hexadecimal (base 16), octal (base 8), or binary (base 2) notation
DeclareABoolean
A Boolean represents two possible states: TRUE or FALSE.
DeclareAFloat
A float (floating point number) is a number with a decimal point or a number in exponential form.
DeclareAnArray
An array stores multiple values in one single variable.
DeclareAConstant
DeclareAGlobalVariable
DeclareAnIntWithNullValue
AssignAVariableValueToAnotherVariable
CastStringIntToBoolean
###Do the same defining return types
Strings
Properties
A string is a sequence of characters, like "Hello world!".
Exercises
Strings definition:
DoubleQuotedStringsAreStrings
SingleQuotedStringsAreAlsoStrings
UseBackslashForEscapingQuotesInStrings
DotConcatenatesStrings
DotWorksWithVariables
DotEqualsAppendsToEndOfString -> .=
String manipulation:
getTheLengthOfAString
CountWordsInAString
ReverseAString
SearchForATextWithinAString
ReplaceTextWithinAString
Operators
Properties
Operators are used to perform operations on variables and values.
Exercises
Arithmetic Operators:
Add
Subtract
Multiplicate
Divide
Module
Exponent
AssignmentOperators:
The PHP assignment operators are used with numeric values to write a value to a variable.
The basic assignment operator in PHP is "=". It means that the left operand gets set to the value of the assignment expression on the right.
AssignVariableToAnotherVariable
AddVariableToAnotherVariable
MultiplyVariableToAnotherVariable
DivideVariableByAnotherVariable
ModuleVariableByAnotherVariable
Comparison Operators:
The PHP comparison operators are used to compare two values (number or string)
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