is there a way in PHP to calc if the operations are in variables as strings? Like this:
<?php
$number1=5;
$number2=10;
$operations="+";
$result = $number1 . $operations . $number2;
?>
2 Answers
Assuming that the code you've given is a pseudo-code...
Given you have a limited set of operations that can be used, you can use switch case.
Using eval() can be a security issue if you are using user input for it...
A switch case example would be:
<?php
$operations = [
'+' => "add",
'-' => "subtract"
];
// The numbers
$n1 = 6;
$n2 = 3;
// Your operation
$op = "+";
switch($operations[$op]) {
case "add":
// add the nos
echo $n1 + $n2;
break;
case "subtract":
// subtract the nos
echo $n1 - $n2;
break;
default:
// we can't handle other operators
throw new RuntimeException();
break;
}
3 Comments
DrSheldonTrooper
yeah I did it like this before but I work with a user input and i dont want to create to many switch cases or ifs
Ikari
yeah... so if you are processing user input, you SHOULD NEVER use eval...
Companjo
@DrSheldonTrooper don't use eval() when processing user input. Use a switch instead. Here an explanation about eval() stackoverflow.com/questions/951373/when-is-eval-evil-in-php
Use eval().
Note: Avoid eval() It is not safe. Its Potential unsafe.
<?php
$number1=5;
$number2=10;
$operations="+";
$result= $number1.$operations.$number2;
echo eval("echo $result;");
Output
15
Demo: Click Here
5 Comments
DrSheldonTrooper
ty, didn't knew about eval
Companjo
eval() is not safe. stackoverflow.com/questions/951373/when-is-eval-evil-in-php
RJParikh
Yes but as per questioner requirement I am helping. @Companjo
Companjo
@RJParikh i understand, but it's better to inform him about the security risks too. Beside that, a switch is a better and safe alternative.
RJParikh
Ok, I forgot it. I have added note. @Companjo
number1=5->$number1=5;