php (midterms 1-3)

• JavaScript and PHP


  Embedded languages - code is embedded within a Web page (either an HTML or XHTML document)
• Writing PHP scripts

  Within code declaration blocks - separate sections within a Web page that are interpreted by the scripting engine
• Statements


  The individual lines of code that make up a PHP script
• Function


  A procedure (or individual statements grouped into a logical unit) that performs a specific task
• Comments


  Lines that contain various types of remarks, including the name of the script, your name and the date you created the program, notes to yourself, or instructions to future programmers
• Comments do not display in the browser
• Variables


  The values a program stores in computer memory
• Identifier


  The name you assign to a variable
• Constant


  Information that cannot change during the course of program execution
• Data type


  The specific category of information that a variable contains
• PHP is a loosely-typed programming language
• Integer


  A positive or negative number or zero, with no decimal places
• Floating-point number


  Contains decimal places or is written in exponential notation
• Boolean value


  A logical value of TRUE or FALSE
• Array


  Contains a set of data represented by a single variable name
• Expression


  A single literal value or variable or a combination of literal values, variables, operators, and other expressions that can be evaluated by the PHP scripting engine to produce a result
• Operands


  Variables and literals contained in an expression. A literal is a value such as a string or a number.
• Operators


  Symbols used in expressions to manipulate operands, such as the addition operator (+) and multiplication operator (*)
• Binary operator


  Requires an operand before and after the operator
• Unary operator


  Requires a single operand either before or after the operator
• Arithmetic operators


  Used in the PHP scripting engine to perform mathematical calculations, such as addition, subtraction, multiplication, and division
• Assignment operators


  Used for assigning a value to a variable
• Comparison operators


  Used to determine how one operand compares with another
• Conditional operator


  Executes one of two expressions, based on the results of a conditional expression
• Logical operators


  Used to perform operations on Boolean operands
• Casting or type casting


  Creates an equivalent value in a specific data type for a given value
• Operator precedence


  The order in which operations in an expression are evaluated
• Function definition


  The lines that make up a function
• Function parameter passed by value


  A local copy of the variable
• Function parameter passed by reference


  A reference to the original variable
• Global variable


  Declared outside a function and available to all parts of your program
• Local variable


  Declared inside a function and only available within the function in which it is declared
• Decision making or flow control


  The process of determining the order in which statements execute in a program
• If statement


  Used to execute specific programming code if the evaluation of a conditional expression returns a value of TRUE
• If...else statement


  An if statement that includes an else clause. The else clause executes when the condition in the if...else statement evaluates to FALSE
• Nested decision-making structures


  When one decision-making statement is contained within another decision-making statement
• Switch statement


  Controls program flow by executing a specific set of statements, depending on the value of an expression
• Loop statement


  A control structure that repeatedly executes a statement or a series of statements while a specific condition is TRUE or until a specific condition becomes TRUE
• While statement


  Tests the condition prior to executing the series of statements at each iteration of the loop
• Do...while statement


  Tests the condition after executing a series of statements