What is the syntax difference between php and java

The difference in syntax between php and java is: in php, user-defined functions, classes, keywords, etc. are not case-sensitive, while variables are case-sensitive; in java, all Function names, keywords, classes, variables, etc. are all case-sensitive.

The basic syntax of Java and PHP is basically the same. In fact, the basic syntax of most languages ​​​​is also the same, but they still have some subtle differences:

1.PHP is a scripting language, the code is executed on the server, and the results are returned to the browser in plain text.

2.PHP can run on a variety of different platforms: such as windows, linux, MaxOS, etc.

3.PHP scripts can be stored anywhere in the document, starting with .

4.PHP comments: PHP supports three comment methods:

A. Double slashes, for example: //This is to declare a variable

B.# symbol, for example : #This is to declare a variable

C./**/ For example: /*This is to declare a variable*/

java also supports three comment methods:

A. Double slashes, for example: //This is to declare a variable

B./**/ For example: /*This is to declare a variable*/

C./***/ For example: /**

*This is to declare a variable

*/

5. Case sensitivity issue in PHP: In PHP, all user-defined functions, classes and keywords (such as if, else, echo, etc.) are not case-sensitive, while variables are case-sensitive. of.

In java, all function names, keywords, classes, variables, etc. are case-sensitive.

6. PHP variable declaration: PHP is similar to Javascript. Both are reference types, and there is no need to specify the type when declaring. Java is a strong reference type, and its type must be specified when declaring.

The way to declare variables in PHP is: $X = 7; Note: The naming rules for java and PHP variables are the same.

7. The scope of variables in PHP:

A. global (global): can only be accessed outside the function

B. Local (local): Can only be accessed within the method body

C.static (static)

Global variables in java are allowed to be accessed within the method.

8.global keyword: You can use the global keyword in the function body to access global variables.

For example:

<span style="white-space:pre">	</span><pre name="code" class="html">
<?php
    $x=5;
    $y=10;
    
    function myTest() {  
    global $x,$y;
      $y=$x+$y;
    }
    
    myTest();
    echo $y; // 输出 15
?>

9. The difference between echo and print in PHP:

echo can output more than one string and is slightly faster than print

print can only output a string and return 1 (unlike java, which can use print to output a line of statements).

Note: In PHP, print can output variables in double quotes, but in java, variables cannot be output in double quotes.

For example:

pre name="code" class="html">$txt2="W3School.com.cn";
echo "Study PHP at $txt2";

同样的也能输出数组中的任意元素：
echo "My car is a {$cars[0]}";

echo and print can be used with or without parentheses. For example: echo and echo();

10. Classes in PHP: The implementation process is the same as that in java, both use the keyword class, but the data declarations are different.

<?php
class Car
{
  var $color;
  function Car($color="green") {
    $this->color = $color;
  }
  function what_color() {
    return $this->color;
  }
}
?>

11.Strings in PHP can be expressed using double quotes or single quotes. But in java only double quotes can be used.

For example: "string" 'string'

This is only part of the foundation. It can be said that these two languages ​​​​have a long history, so they have similarities but no differences.

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