How to write the response of a function to a variable?

Question

PHP

I have a function that cannot be changed, when called, I get an echo in response. Can I somehow write this answer into a variable beforehand, and only then display it? Now the result is not written to the variable, but is displayed immediately.

Example (conditional!):

function test() {
    //...
    $a = 100;
    echo $a;
}
$b = test();

Answer 1

Use buffering:

ob_start();
test();
$b = ob_get_clean();