将变量中的数字替换为for循环中的另一个变量

I'm trying to produce 25 variables from $day1Txt through to $day2Txt.

How do I turn the '1' in the variable $day1Txt into the variable $i?

for ($i = 1; $i < 25; $i++) { 

        $day1Txt = echo call_user_func('Day_'.$i.'_Offer', 'EMAIL_OFFER'); 

}

I've made an attempt myself but it white screens...

  ${'day'.$i.'Txt'} = echo call_user_func('Day_'.$i.'_Offer', 'EMAIL_OFFER'); 

This should help you(remove echo).

for ($i = 1; $i < 25; $i++) {

        ${"day".$i."Txt"} =  call_user_func('Day_' . $i . '_Offer', 'EMAIL_OFFER');
    }

If you want to see what all variables are there in your function use get_defined_vars().

See deme here

Try this

for ($i = 1; $i < 25; $i++) { 

        ${"day".$i."Txt"} = call_user_func('Day_'.$i.'_Offer', 'EMAIL_OFFER'); 

}

It's called Variable variables ie a variable name which can be set and used dynamically