HTML forms are used to collect some data from the site visitor. The HTML <form>…..</form> tag is used to create an HTML form
<input>
<textarea>
<button>
<select>
<option>
<optgroup>
<fieldset>
<label>
<input> tag prompts the user to enter data and also request for the information from the web server after submitting the web form.
How it is Used?
<form>
<input>
</form>
PHP has a number of functions for reading data from files. You may read entire file data, read data line by line, or read data character by character using various methods.
The available PHP file read functions are given below.
Reads a file and publishes it to the output buffer with the readfile() method.
Assume we have a text file on the server named “webdictionary.txt” that looks like this:
AJAX = Asynchronous JavaScript and XML
CSS = Cascading Style Sheets
HTML = Hyper Text Markup Language
PHP = PHP Hypertext Preprocessor
SQL = Structured Query Language
SVG = Scalable Vector Graphics
XML = EXtensible Markup LanguageThe following is the PHP code for reading the file and writing it to the output buffer (the readfile() method returns the number of bytes read if successful):
Example:-
If all you want to do is open a file and read its contents, the readfile() method comes in handy.
<!DOCTYPE html>
It defines a scalar measurement within a known range or a fraction value. This is also known as a gauge. It should not be used to indicate the progress bar. If the browser doesn’t support the meter tag then it will show text written between the opening meter tag and the closing meter tag.
Ex:-
<meter value=“20” max=“100” min=“10”>Range</meter>
<meter low=”60″ high=”80″ value=”100″ max=”100″>Range</meter>
| Attribute | Value | Description |
| value | Number | Specifies the current value of the meter. This must be between the min and max values. |
| form | Form_id | It associates the <meter> with a <form> |
| high | Number | It specifies the range that is considered to be a high value. This must be less than the max value. |
| low | Number | It specifies the range that is considered to be a low value. This must be greater than min value. |
| max | Number | It specifies the max value of the range. |
| min | Number | It specifies min value of the range. |
| optimum | Number | It specifies what value is the optimal value for the meter. |
<figure>
<img src=“image.jpg" width="304" height="228">
<figcaption>Picture One</figcaption>
</figure>
The id attribute specifies a unique id for an HTML element. The value must be unique within the HTML document.
The id attribute is mostly used to point to a style in a style sheet, and by JavaScript (via the HTML DOM) to manipulate the element with the specific id. The id attribute can be used on any HTML element.
<html>
<head>
<title> id attribute</title>
<style>
#top{
color: blue;
}
#imp{
color: brown;
}
</style>
</head>
<body>
<a href="#imp">Important</a>
<p id="top">
Once upon a time, all the birds - the swans, cranes, </p>
<h3 id="imp">
Goodwill is that unseen force which is </h3>
<p>He has neither the time, nor the interest to bother </p>
<a href="#top">Go to Top</a>
</body>
</html>
The HTML class attribute makes it possible to define equal styles for elements with the same class name. The class attribute specifies one or more class names for an element. The class attribute is mostly used to point to a class in a style sheet. However, it can also be used by JavaScript (via the HTML DOM) to make changes to HTML elements with a specified class.
In HTML5, the class attribute can be used on any HTML element.
<html>
<head>
<title>class tag</title>
<style>
.red {color: #FF0000; font-size: 60px;}
</style>
</head>
<body>
<h2 class=red> Heading line </h2>
<p class =red>1st paragraph line</p>
<p> paragraph tag </p>
</body>
</html>
To specify multiple classes, separate the class names with a space. This allows you to combine several CSS classes for one HTML element. Syntax:- class=“class_name1 class_name2 class_nameN” Ex:- <p class =“red look”>I am first paragraph</p>
<html>
<head>
<title>class name twice or max </title>
<style>
p.red {color: #FF0000;}
p.look{font-size: 100px;}
.algn{text-align: center;}
</style>
</head>
<body>
<h2>I am Heading</h2>
<p class ="red look"> first paragraph</p>
<p class="red algn">second paragraph</p>
</body>
</html>
The <style> tag is used to declare style sheets within the head of HTML document. Inside the <style> element you specify how HTML elements should render in a browser. Each HTML document can contain multiple <style> tags.
| Attribute | Value | Description |
| media | media_query | Specifies what media/device the media resource is optimized for |
| scoped | scoped | Specifies that the styles only apply to this element’s parent element and that element’s child elements |
| type | text/css | Specifies the media type of the <style> tag |
<html>
<head>
<title>html_style</title>
</style>
</head>
<body style="background-color: rgb(180, 221, 67);">
<h1 style="text-align: center;">Style tag</h1>
<p style="margin-bottom: auto;">Lorem ipsum dolor sit amet, consectetur adipisicing elit. Ullam, nobis.</p>
<hr>
<br>
<p style="color: blue;">Lorem ipsum dolor sit amet consectetur adipisicing elit. Fuga, eligendi?</p>
</body>
</html>
Function are those callable section of code that you can pass data to, and that can return data to you. Function are subprograms which are used to compute a value or perform a task.
Syntax:-
function function_name( )
{
Block of statement;
}
Example:-
Numeric arrays allow us to store numerous values of the same data type in a single variable rather than creating multiple variables for each value. These values can then be accessed using an index, which is always a number in numeric arrays.
There are two ways to create an array. Let’s take a look at both these ways in the Following example:
You must know the index value of an array’s items in order to access them.
Example:-
The in-built function count can be used to count the length of an array, or the number of elements in the array.
Example:-
A loop is an Iterative Control Structure that requires the same number of codes to be executed several times until a specific condition is met. When writing code, you may want a specific block of code to run a certain number of times. As a result, rather than applying nearly similar code lines to a script, we can employ loops.
Loops are used repeatedly to run the same piece of code as long as a given condition is met. A loop’s basic premise is to simplify recurring procedures in a programmer in order to save time and effort. PHP supports four different loop styles.
while – Loops through a code block as long as the given condition is true.do...while – The code block running once and then is tested. State. If the condition is true, the declaration shall be repeated until the condition stated is true.for – Loops via a code block before a given number is reached in the counter.foreach – Loops for each unit of an array across a block of code.When trying to recreate code, it might be tedious to retype or copy and paste the same code over and over again. Worse, unintentional mistakes might lead to programme malfunctions.
That’s quite a few keystrokes! What if you decide later that you want to start each statement with “The count is currently: ”? You’d have to copy it and paste it into every single line.
Fortunately, loops are a function in most programming languages that allows you to automatically repeat code before such requirements are met. Iteration is a phrase used to describe the repetition of code, and it refers to each time the code is executed. Loops will reduce the number of lines of code you write while still allowing you to update it later.
PHP is no exception, as it offers a variety of ways to repeat the execution of a code block.
This Article has cover the following PHP loop types:
whiledo … whileforforeachThere are conditions in each of these loops that prevent the loop from executing. If these requirements are not met, an endless loop will follow, and the software will never be able to quit executing the code block.
In order to write effective code, any programmer needs have a thorough understanding of loops and how to use them effectively in programming.
When writing code, we must always repeat a same set of functions. Performing them one at a time would result in a higher number of lines of code and a longer duration. As a result, the software gets more difficult to understand. As a result, instead of using loops to run the code, we can use them!
A function is a segment of code in a program that is written to do a certain task. We should compare functions to workers in a real-world workplace to have a better grasp of how they work. Assume the management delegated the duty of determining the annual budget to one of his employees. So, what will be the outcome of this procedure? The employee would ask his supervisor for data, perform estimations, calculate the budget, and report the results to his superior. Functions work in a similar fashion. They accept data as an argument, process it using a set of statements or operations, and then return the output.
There are Two Types of Functions :-
User Defined Functions:-These capabilities are used by developers and programmers when they need to execute their own logic. This functions are specified with the keyword function, and when a function call is made, a sequence of statements will be written within the function to execute it. Simply type functionname() in the address bar, and the function will be run.
Built-in functions:- These routines offer us with already-built-in library functionality. The PHP installation kit includes several capabilities, making the language more efficient and helpful. To use the function’s attributes, all we have to do is call it when we want the desired outcome. PHP makes use of date, numeric, string, and other built-in functions.
Reusability:- This programming language has a feature that reduces the amount of lines of code that must be written many times. This would save time and effort for the developer or coder. We can put a piece of code in a feature and call it whenever and wherever it’s needed if it has to be used in many locations. This may be done by calling the functions from other programmes or from inside the same package.
Easier Error Detection:- Because the code is written as functions rather than single blocks, any problems may be immediately and readily recognized and rectified.
Easily Maintained:- Because functions are used throughout the program, we may quickly modify any function or line of code in the function, and the change will be reflected. As a result, it is simple to maintain everywhere.
A function is to find a collection of statements in a programmer repeatedly. When a function in a program is invoked, it is simply implemented. There are a few things to keep in mind while creating a user-identified feature.
Example:-
