quotes

What is the difference between the quotes " and ' ? What about `? Is there an error in using different quotes ' and " below? $result = pg_query_params($dbconn, 'INSERT INTO users (username, email, passhash_md5) VALUES ($1, $2, $3)', array($username, $email, $passhash_md5 ) $result = pg_query_params( $dbconn, "SELECT user_id FROM users WHERE email = $1", array( $email ) ) Variable-substitution isn't done when using single quotes ('), meaning that the values in your first example would literally be $1 $2 etc if it was a regular string and not passed on to a function that replaces them. If you

Can there be quotes around JSON numbers? In most of the search links, it seems that numbers do not "require" quotes. But, should the parsers accept both "attr" : 6 and "attr" : "6" ? If MyParser has a method getInt to get a number given the key, should MyParser.getInt("attr") return 6 in both cases, or throw an exception in the latter case? In JSON , 6 is the number six. "6" is a string containing the digit 6 . So the answer to the question "Can json numbers be quoted?" is basically "no," because if you put them in quotes, they're not numbers anymore. But, should the parsers accept both "attr"

EDIT: the command substitution is not necessary for the surprising behavior, although it is the most common use case. The same question applies to just echo "'!b'" b=a # Enable history substitution. # This option is on by default on interactive shells. set -H echo '!b' # Output: '!b' # OK. Escaped by single quotes. echo $(echo '!b') # Output: '!b' # OK. Escaped by single quotes. echo "$(echo '$b')" # Output: '$b' # OK. Escaped by single quotes. echo "$(echo '!b')" # Output: history expands # BAD!! WHY?? In the last example, what is the best way to escape the ! ? Why was it not escaped even if

How can I replace "" (I think it's called double quotes) with '' (I think its called single quotes) using PHP? str_replace('"', "'", $text); or Re-assign it $text = str_replace('"', "'", $text); Use $str = str_replace('"','\'',$str) Try with preg_replace, <?php $string="hello \" sdfsd \" dgf"; echo $string,"\n"; echo preg_replace("/\"/","'",$string); ?> You can use str_replace, try to use http://php.net/manual/en/function.str-replace.php it contains allot of php documentation. <?php echo str_replace("\"","'","\"\"\"\"\" hello world\n"); ?> Try with strtr, <?php $string="hello \" sdfsd dgf";

How do you nest quotes in HTML beyond the second level? As far as I know, there are only 2 types of quotes - single(') and double("). I am aware of escaping using slashes - you have to escape in the code but that escaping won't work at the browser level. What is the accepted method to get around something like the following? <p onclick="exampleFunc('<div id="divId"></div>');">Some Text</p> That code prints to the browser: ');">Some Text You need to use proper escaping/encoding. Either in HTML using character references: <p onclick="exampleFunc('<div id="divId"></div>');">Some Text</p> Or in

How can I get PHP to evaluate a static variable in double quotes? I want to do something like this: log("self::$CLASS $METHOD entering"); I've tried all sorts of {} combos to get the variable value of self::$CLASS, but nothing has worked. I've currently settled with string concatenation but it is a pain to type: log(self::$CLASS . " $METHOD entering"); Sorry, you can't do that. It only works for simple expressions. See here . micropro.cz Unfortunately there is no way how to do this yet. Example in one of answers here will not work, because {${self::$CLASS}} will not returns content of self::