为什么PHP echo printf添加意外符号[重复]

Question

This question already has an answer here:

• php printf adds number to output 2 answers

I have php code:

$searchTitlePersonType = ($isTravelAgency == true ? "tourists" : "persons"); 
var_dump($searchTitlePersonType); // Right behavior

The same time, when I try to implement it on my template:

<?php
    echo printf( $this->translate("Поиск %s"), $searchTitlePersonType ); 
?>

I'm taking different unexpected numbers at the end of string: "tourists33" or "persons27". It's not depend of coding page of string and there is a lot of people who find the way to resolve it - do not combine echo printf in one line of code, but here my question about this problem: WHY does it happen?

Links:

php printf adds number to output

PHP printf adds something after formatted string

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Answer 1

You are confusing some things here. echo printf as a construct does not make sense, since printf already prints.

What you are seeing, is that printf does its job, and then echo prints the result of printf, which is the length of the printed string.

So, instead, you can use sprintf, which returns the formatted string instead of printing it, or you can skip the echo part of your program.