What is function? Functions are sets of statements, which can be stored and kept separately from the main script and perform particular tasks. Functions offer a simple means to make reusable code blocks that are much easier to debug and more portable.
There are several ways to define a function. In the case of Java, the syntax is to use a module-level keyword. For PHP, it is best to use a “unary”comma-delimited” form of the same function. The next two sections will show you how to write and use functions for your scripts.
When using function inside of your script, there are two ways to start it out. A first form of function definition is to start with an assignment statement. This is usually written as a single quote mark followed by the function name. For example, a simple line of code that defines a function would look like this:
A second way to start a function is with a return statement. For example, here is a basic function that takes a parameter and returns the first number after the function is executed. Note the use of the commas around the function name:
Now, for a more complex example of a function. It is best to start out with a “return” statement to get a basic idea of how the function works. Inside of this statement, it would look like this:
In this example, we have defined a function’s return with a single quote mark followed by its name. Now, it is time to write and then call this function. The syntax for a simple function is like this:
If you find yourself having trouble getting this down, here are a few examples of functions that you can use. The following two examples are used to demonstrate the use of the “if”else” statements.
Hopefully, your program ends up with something like this:
While this may not be a very impressive statement, it demonstrates the basic concepts of how a function works. When you are defining a function, you need to remember that the function’s name is the first thing that is seen. After that, the next things to see are the function’s arguments.
To show what the function’s arguments are, you will need to place a”?” after each set of words.
Names of arguments are the next thing you will see. You will need to put the name of each one. Here is an example:
If you find the name of a particular argument confusing, there are a number of different ways to explain that:
These arguments come after the names of the function’s names. If you need to show the name of a particular argument, just replace the? with another variable name.
What is the function is all about is getting to know how to use function correctly. The above three examples should help you out.
After you understand the function’s arguments, you will need to find out how to do the function’s actual work. This part is where it gets interesting.
To show you how to write and use a function, I have given you three basic examples. However, in order for you to get more complex ones down pat, you will need to learn more.
Once you understand how to write and use a function, you can begin to understand how to do complex functions. To start with, you need to be able to use a function to make a difference in the value of its own and its arguments. Then, you need to be able to make a difference between an argument and its value.
Finally, you need to be able to make a difference between a parameter and the parameter of a function. These are the basics that you will need to be able to use in most situations.
