2016-04-06 When is the Spring Festival in 2016? Year of the Monkey 2016? Tomb-Sweeping Day Holiday Schedule 2016

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PHP tag

• Form one

  <code><?php  ?>
  </code>

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• Form two

  <code><script language="php"></script>
  </code>

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• Form three

This form needs to rely on a configuration in php.ini short_open_tag = On

<code><? ?>
</code>

If there is no html behind php, can it be omitted?>

PHP case-sensitive feature

• Variable differentiation

• Constant differentiation

• Others are not differentiated

About points The number

• should be added to every sentence;

• The last sentence in a php tag does not need to be added;

• If the end tag is omitted, the last sentence cannot be omitted;

About comments

• Single-line comments // or #

• multi-line comments /% %/

Variables

• There is no simple definition

• isset to determine whether the variable exists

<code>$v1 = isset($s1);  // false
$s2 = 1;
$v2 = isset($s2); //true</code>

• unset deletes variables

<code>$v1 = 1;
isset($v1); //true
unset($v1);
isset($v1); // false</code>

The variable names that can be used

• start with letters or underscores

• followed by any number (including 0) of letters, numbers and underscores

Naming rules

• Camel nomenclature: the first word is lowercase, and the first letter of each subsequent word is capitalized

<code>$name   $myName   $myFatherName</code>

• Pascal nomenclature: the first letter of each word is capitalized

<code>$Name   $MyName   $MyFatherName</code>

• underscore separation method: each Words are lowercase and separated by underscores

<code>$name   $my_name   $my_father_name</code>

Variable value transfer method

Value transfer

The values ​​​​of two variables do not affect each other

Reference transfer

Values ​​affect each other

<code>$m1 = 1;
$m2 = & $m1</code>

The above introduces 2016-04-06, including the content of 2016. I hope it will be helpful to friends who are interested in PHP tutorials.