PHP Basics. The difference between PHP and JS

1. PHP uses a dot for a spelling string.

JS with a + number.

2. PHP files to be placed in the Wamp file inside the www.

3. PHP and JS are embedded in the same way, but the embedded tag is not the same.

4. PHP output syntax with ECHO. You can output multiple strings. The special output method is Var_dump ().

5. PHP defines a variable with a $.

6. PHP Special definition Way $ variable =<<<a

A

Be aware that the following a should be shelf written.

7. echo "he" \llo "PHP parsing escaped double quotes Yes, single quotes not available."

8. PHP casts strings string for example $a = (string) $a;

Settype ($a, "string");

9. 　　PHP variable common function unset ($a); Delete a variable
Var_dump (Isset ($a)); Determine whether a variable exists;
Var_dump (Empty ($a)); The judgment is empty, the variable does not exist, the variable is equal to zero, the empty string is empty

10.   PHP variable take address & represent variable take address for example: $a = 10;   $b =& $a;     Echo $b; So the output variable is 10

11.    PHP mutable variables such as $a = "Hello";   $hello = "Zhang San";    echo $ $a; This output is Zhang San

12. PHP inside @ stands for suppress error symbol

13. $a = 10;
echo $a ==10? " OK ":" NO ";

Trinocular operator

14. PHP Error Tip: Notice alert Warning Warning Error

PHP Basics. The difference between PHP and JS