PHP koans

Run: composer install

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Variables:

Properties:

• 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

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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

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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)

  • Equal
  • Identicla
  • NotEqual
  • NotIdentical
  • GreaterThan
  • LessThan
  • GreaterThanOrEqualTo
  • LessThanOrEqualTo