Detailed explanation of the use of var_dump method in PHP_PHP tutorial

First look at the example:

Copy the code The code is as follows:

$a = "alsdflasdf;a";
$b = var_dump($a);
echo "
";
//var_dump($c);
$ d=var_dump($c);
echo "
";
echo $a;
echo "
";
echo $b;
echo "< ;br>";
Output:
string(12) "alsdflasdf;a"
NULL
alsdflasdf;a

What does it mean? The var_dump() method determines the type and length of a variable and outputs the value of the variable. If the variable has a value, it outputs the value of the variable and returns the data type. This function displays structural information about one or more expressions , including the type and value of the expression. Arrays will expand values ​​recursively, showing their structure through indentation.
Its format: var_dump ( mixed expression [, mixed expression [, ...]] )
Let’s take a look at var_dump syntax:
var_dump (var,var,bar);
One thing to note is that the variables in var_dump must exist. If the variable exists but the value is empty, false will be returned; if there is no variable, NULL will be returned. Himself There is an output function. No need to add other output functions.

http://www.bkjia.com/PHPjc/327812.htmlwww.bkjia.comtruehttp: //www.bkjia.com/PHPjc/327812.htmlTechArticleFirst look at the example: Copy the code as follows: ?php $a = "alsdflasdf;a"; $b = var_dump($a); echo "br"; //var_dump($c); $d=var_dump($c); echo "br"; echo $a; echo "br"; echo $b; ec...