Is it possible to access the same argument twice in sprintf?

Question

In PHP times the function sprintf. With it we can format the values sequentially passed from the second parameter.

For example:

sprintf('Meu nome é %s e tenho %d anos de idade', 'Wallace', '26')

The exit will be

My name is Wallace and I’m 26 years old

But at a given moment I needed to have a functionality similar to those that exist in languages like Python or C#, where you can repeat in the format string one of the arguments passed.

For example in Python

 s = "Meu nome eh {0}. Sim, o meu nome eh {0}. Eu tenho {1} anos de idade"
 s.format('Wallace', 1)

The exit would be:

u"My name is Wallace. Yes, my name is Wallace. I am 1 years old"

Note that the parameter "Wallace" repeated itself without the need to pass it twice.

Using the sprintf PHP, I need a similar solution. It is possible to do the same operation as in Python PHP, using the function sprintf?

Note: I would like to know specifically about the function sprintf.In this case, user-created functions would not be welcome as a response.

Answer 1

According to the function documentation sprintf, you must use the character $ preceded by a number, which represents the number of the argument you want to capture, and preceded by the desired formatting flag (for example, s, f or d).

The count of arguments starts from the number 1. The expression needs to be initialized by %, like all other ways used to format an argument in functions sprintf/printf.

Then, we could write the format string like this:

$tpl = 'Meu nome eh %1$s. Sim, o meu nome eh %1$s. Eu tenho %2$d anos de idade';

echo sprintf($tpl, 'Wallace', '26')

We read the code as follows:

%1$s "Replace this token with the first argument (Wallace) and format it as string.

%2$d "Replace this token with the second argument (26) and format it as an integer.

Functional example

Answer 2

The response of @Laerte is great and very correct, but I decided to leave two alternatives the answer just to make writing more practical tokens, resembling str.format python:

Suggestions 1:

I will post the example that the @Gumbo made/posted this function:

function format() {
    $args = func_get_args();
    if (count($args) == 0) {
        return;
    }

    if (count($args) == 1) {
        return $args[0];
    }

    $str = array_shift($args);
    $str = preg_replace_callback('/\\{(0|[1-9]\\d*)\\}/', create_function('$match', '$args = '.var_export($args, true).'; return isset($args[$match[1]]) ? $args[$match[1]] : $match[0];'), $str);
    return $str;
}

Use:

$str = 'Meu nome eh {0}.
        Sim, o meu nome eh {0}.
        Eu tenho {1} anos de idade.
        {0} {1} {1} {0}';

echo format($str, 'Wallace', 26);

Suggestions 2:

This I created now, is basically the vsprintf mixed with preg_replace

<?php
function format() {
    $args = func_get_args();
    if (empty($args)) {
        return null;
    }

    if (count($args) === 1) {
        return $args[0];
    }

    $str = array_shift($args);
    $str = preg_replace('#\{(\d+)\}#', '%$1\$s', $str);

    return vsprintf($str, $args);
}

Use:

The {0} is not supported, so always starts from 1

$str = 'Meu nome eh {1}.
        Sim, o meu nome eh {1}.
        Eu tenho {2} anos de idade.
        {1} {2} {2} {1}';

echo format($str, 'Wallace', 26);

Online example: http://ideone.com/0uf7cr