尝试用字符串中的+替换所有空格

Question

I'm trying to replace all spaces with +'s in a string, but after I do the preg_replace(), I get a blank string as the result.

Why? What am I doing wrong?

$query = "hello world";
$formattedQuery = preg_replace('\s', '+', $query);
echo "formatted Query is: ".$formattedQuery;
/* output should be hello+world, but I am getting nothing / blank string outputted */

Answer 1

Why not use str_replace()

$query = "hello world";
$formattedQuery = str_replace(' ', '+', $query);
echo "formatted Query is: ".$formattedQuery;

If your insist on using preg_replace() then turn the first parameter into a regular expression:

$query = "hello world";
$formattedQuery = preg_replace('/\s+/', '+', $query);
echo "formatted Query is: ".$formattedQuery;

Answer 2

If you are working with data over URL what you actually need is urlencode not replace spaces

$query = "hello world";
echo urlencode($query);

If Not then you can use

echo preg_replace('/\s+/', "+", $query);

Output

hello+world

Answer 3

对于preg_replace，请尝试：

preg_replace('/\s+/', '+', $query);

Answer 4

$ formattedQuery = preg_replace（'/ \\ s /'，'+'，$ query）;