Haunted! Php string array crossover

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$ Where = '1 = 1'; $ keyword = $ _ GET ['keyword']; if ($ keyword) {$ where ['title'] = array ('like', "% $ keyword %");} var_dump ($ where); printed out: A = 1 What is the conversion process?

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$ Where = '1 = 1'; $ keyword = $ _ GET ['keyword']; if ($ keyword) {$ where ['title'] = array ('like', "% $ keyword %");} var_dump ($ where); printed out: A = 1 What is the conversion process?

First, let me vomit (it will die if you don't speak !) :

1. $whereIs a string, you write$where['title']What is it?

2. You putarrayAssign a value to a string. What is this?

After removing some useless code from your problem, let's streamline the problem:

$where = '1=1';$where['title'] = array();var_dump($where);

What corresponds to the above vomit is that we also look at it step by step:
$where['title']Represents a string.$whereAs'title'Note that the valid value of the sub-Mark is [0-the length of the string minus 1]. for php, the invalid subscript is actually$where[0]Is consistent.
The problem is further simplified:

$where = '1=1';$where[0] = array();var_dump($where);

Understand$where[0]Actually, it refers$whereThe first character of the string.You putarrayAssign a value to a string. What is this?"
Here is a test:

var_dump( (string)array() );

What do you guess will be output?

PHP Notice:  Array to string conversion in /home/nfer/temp.php on line 8string(5) "Array"

So here is a good understanding,$where[0] = array();Is to put the stringArrayAssigned$whereThe first character of the string.
Bingo, the output isstring(3) "A=1"

Finally, let me writeHauntedCode:

$where = 'A=1';$keyword = $_GET['keyword'];        if($keyword) {    $where['title'] = $keyword == 123;}var_dump($where);

What do you think the results will output?

1. $ where = 1. this is correct. first, this is a string.
2. then you use $ where as an array and assign $ where ['title'] = array ('like', "xxx") to the array. this is unscientific.