i need help with this, currently my idea here is to only use variables to perform an IF statement, these variables are supposed to be taken from a database (ive got that down) but i dont know how to create an if statement that can use all 3
<?php
$Anum="10";
$Bnum="30";
$MOD="<=";
if ($Anum $MOD $Bnum)
{
echo $Anum, " is smaller than ", $Bnum;
}
else
{
echo "$Anum, " is not smaller than ", $Bnum;
}
?>
This will work for you:
$Anum="10";
$Bnum="30";
$MOD=">=";
eval("\$result = ($Anum $MOD $Bnum) ? true : false;");
if ($result) {
echo "$Anum is smaller than $Bnum";
} else {
echo "$Anum is not smaller than $Bnum";
}
Output:
10 is not smaller than 30
BUT.
PHP has variable variables and can expand strings into variables with it, but it does not work for language constructs, only for variables. ">=" is a comparison operator, so by this:
$Anum.$MOD.$Bnum
//or this
"$Anum $MOD $Bnum"
or this
"{$Anum} {$MOD} {$Bnum}"
You can only get a string, which will always give you true when using with if statement. To achieve what you want with your strategy you need to use eval. But it is a function, that should be avoided, unless you have enough experience and knowledge to use it with all responsibility and caution.
In php
$MOD="<=";will assign as a string (double quoted characters)
For assigning this as a comparison operator you have to do something like this
<?php
$Anum=10;
$Bnum=30;
$MOD=">=";
switch ($MOD) {
case '<=': if($Anum <= $Bnum){ echo $Anum ." is smaller than ". $Bnum;} else{ echo $Anum ." is not smaller than ". $Bnum; }; break;
case '>=': if ($Anum >= $Bnum){ echo $Bnum ." is smaller than ". $Anum;} else{ echo $Bnum ." is not smaller than ". $Anum; }; break;
}
?>
try this
<?php
$Anum="10";
$Bnum="30";
$MOD="<=";
$result = eval("if($Anum $MOD $Bnum){return true;}else{return false;}");
if ($result)
{
echo $Anum. " is smaller than ". $Bnum;
}
else
{
echo "$Anum, is not smaller than ". $Bnum;
}?>
here
eval("if($Anum $MOD $Bnum){true}else{false}");
will execute the if condition and return the result and save it to some variable, and put this variable to if statment.
eval statement won't run.