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Open Source Technologies

Notes • An array in PHP is actually an ordered map. A map is a type that associates values to
keys.

• The main difference in OOP as opposed to functional programming is that the data and
code are bundled together into one entity, which is known as an object.

7.11 Keywords

Multi-Dimensional Arrays: When accessing nested arrays, you can just add as many square
brackets as required to reach the relevant value. The following is an example of how you can
declare nested arrays.
Arrays: An array in PHP is a collection of key/value pairs. This means that it maps keys (or
indexes) to values.
Default Parameters: Default parameters like C++ are supported by PHP. Default Parameters
enable you to specify a default value for function parameters that aren’t passed to the function
during the function call.

Returning Values By Reference: PHP also allows you to return variables by reference.
Declaring Function Parameter: There are two different ways of passing these arguments. The
first is the most common, which is called passing by value, and the second is called passing by
reference. Which kind of argument passing you would like is specified in the function definition
itself and not during the function call.

By-Value Parameters: Here, the argument can be any valid expression, the expression is
evaluated, and its value is assigned to the corresponding variable in the function.

By-Reference Parameters: Passing by-reference requires the argument to be a variable. Instead
of the variable’s value being passed, the corresponding variable in the function directly refers
to the passed variable whenever used.

Static Variables: Static variables can be initialized, and this initialization only takes place the
first time the static declaration is reached.

Accessing Array Elements: Array elements can be accessed by using the $arr[key] notation,
where key is either an integer or string expression.
Objects: The main difference in OOP as opposed to functional programming is that the data
and code are bundled together into one entity, which is known as an object.

e’re going to implement a recursive function in MIPS. Recursion is one of those
programming concepts that seem to scare students. One reason is that recursive
Wfunctions can be difficult to trace properly without knowing something about
how a stack works.
“Classic” recursion attempts to solve a “big” problem by solving smaller versions of the
problem, then using the solutions to the smaller versions of the problem to solve the big
problem.
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