Wednesday, 26 June 2019

Ch-4 Basic of PHP Script


Ch-4 Basic of PHP Script
PHP syntax:
Php script can only be write within (<? Php    ?> ) tag, save by .php extension and save in xampp\htdocs.
For example : if you want to print hello world , you have to  do following-
Open notepad or notepad++,  then write there following code:
<?php
echo “hello world”;
?>
Save this program by any name suppose test1 and also this name is followed by .php extension. Like(test1.php) .
This program simply print hello world on PHP Server.
Echo
echo is a print command. In place of echo you may be write print. For ex.
<?php
print "good morning";
?>
Output :good morning

Print and echo
 Remember that, echo and print is a language constructs not a function. Function is always followed by () parenthesis.
In echo and print , this is your wish to apply or not apply () parenthesis with them.
Both are a language constructor . both can be write without double inverted quotes(”), but remember without quotes you cannot write more than one word. For example
<?php
print good;
?>
Output :good

There is also no necessity to apply semicolon(;) at end of instruction.
Difference between echo and print:
1.     echo does not have return argument, but print have a return argument 1. So, we can say that echo is faster than print.
2.   echo can consider more than one string like:
<?php
echo "good","morning";
?>
       Output :good morning
But print cannot consider more than one string
<?php
print "good","morning";
?>
It gives a parse error.

Use of HTML in PHP
In case, if you want to design your page by background color,text color etc , you have to embedded this  tag within html program. Like:
<html>
<head><title>first program</title></head>
<body bgcolor="red" text="green" >

<?php
echo "hello world";
?>
</body>
</html>

Technical Interview Question

1. How can PHP and HTML interact?
2.What are the main error types in PHP and how do they differ?
3. What is "echo" in PHP?
4.What is "print" in PHP?
5. What is the difference between "echo" and "print" in PHP?









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