PHP str_replace replace spaces with underscores

问题

Is there a reason that I'm not seeing, why this doesn't work?

    $string = $someLongUserGeneratedString;
    $replaced = str_replace(' ', '_', $string);
    echo $replaced;

The output still includes spaces... Any ideas would be awesome

回答1:

I'll suggest that you use this as it will check for both single and multiple occurrence of white space (as suggested by Lucas Green).

$journalName = preg_replace('/\s+/', '_', $journalName);

instead of:

$journalName = str_replace(' ', '_', $journalName);

回答2:

Try this instead:

$journalName = preg_replace('/\s+/', '_', $journalName);

Explanation: you are most likely seeing whitespace, not just plain spaces (there is a difference).

回答3:

For one matched character replace, use str_replace:

$string = str_replace(' ', '_', $string);

For all matched character replace, use preg_replace:

$string = preg_replace('/\s+/', '_', $string);

回答4:

Try this instead:

$journalName = str_replace(' ', '_', $journalName);

to remove white space

来源：https://stackoverflow.com/questions/12704613/php-str-replace-replace-spaces-with-underscores