How to resolve must be an instance of string string given prior to PHP 7

0 votes

Here is my code:

function phpwtf(string $s) {
    echo "$s\n";
}
phpwtf("Type hinting is da bomb");

Which results in this error:

Catchable fatal error: Argument 1 passed to phpwtf() must be an instance of string, string given

Apr 20, 2020 in PHP by kartik
• 37,520 points
5,166 views

1 answer to this question.

+1 vote

Hello,

Prior to PHP 7 type hinting can only be used to force the types of objects and arrays. Scalar types are not type-hintable. In this case an object of the class string is expected, but you're giving it a (scalar) string. The error message may be funny, but it's not supposed to work to begin with. Given the dynamic typing system, this actually makes some sort of perverted sense.

You can only manually "type hint" scalar types:

function foo($string) {
    if (!is_string($string)) {
        trigger_error('No, you fool!');
        return;
    }
    ...
}
answered Apr 20, 2020 by I Navin
• 220 points

Related Questions In PHP

0 votes
1 answer
0 votes
0 answers

How to sort an array of associative arrays by value of a given key in PHP?

Given this array: $inventory = array( ...READ MORE

Jul 24, 2022 in PHP by Kithuzzz
• 38,000 points
670 views
0 votes
1 answer

How to resolve the problem of losing a session after a redirect in PHP?

Hello @kartik, Carry out these usual checks: Make sure session_start(); is ...READ MORE

answered Aug 24, 2020 in PHP by Niroj
• 82,840 points
35,160 views
0 votes
1 answer

How to check if a string is an email address in PHP?

Hello, Try this without regular expressions: <?php ...READ MORE

answered Nov 3, 2020 in PHP by Niroj
• 82,840 points
4,005 views
0 votes
1 answer

How to check an IP address is within a range of two IPs in PHP?

Hello @kartik, With ip2long() it's easy to convert your addresses ...READ MORE

answered Nov 3, 2020 in PHP by Niroj
• 82,840 points
3,644 views
+1 vote
1 answer

How to make anchor tag with routing using Laravel?

Hey @kartik, First you have to go to ...READ MORE

answered Mar 18, 2020 in Laravel by Niroj
• 82,840 points
23,085 views
0 votes
1 answer

What is redirection in Laravel?

Named route is used to give specific ...READ MORE

answered Mar 18, 2020 in Laravel by Niroj
• 82,840 points
3,017 views
0 votes
1 answer

How to install Laravel via composer?

Hello, This is simple you just need to ...READ MORE

answered Mar 23, 2020 in Laravel by Niroj
• 82,840 points
2,951 views
+1 vote
1 answer

What are named routes in Laravel and How can specify route names for controller actions?

Hey @kartik, Named routing is another amazing feature of ...READ MORE

answered Mar 23, 2020 in Laravel by Niroj
• 82,840 points
44,893 views
0 votes
1 answer

How to set up file permissions for Laravel?

Hello @kartik, The permissions for the storage and vendor folders should stay ...READ MORE

answered Apr 20, 2020 in PHP by I Navin
• 220 points
4,406 views
webinar REGISTER FOR FREE WEBINAR X
REGISTER NOW
webinar_success Thank you for registering Join Edureka Meetup community for 100+ Free Webinars each month JOIN MEETUP GROUP