<?php
$x = 400;
$y = 0.75;
$z = 1.5;
$test = ($x + 2 * $y - ($x / 2 + 2 * $z)) / 2;
print $test;
// 99.25
A = 1 какю-нибудь строчку повеселее, типа A = 1; exec(rm -rf /)*, то можно огрести проблем.
$tmp_ar=array ('x1', 'x2', 'y1', 'y2');
foreach ($lines as $line){
for ($i=0; $i<4; $i++)
{
$tmp=$tmp_ar [$i].'_'.$line ['number'];
$$tmp=$line [$tmp_ar [$i]];
}
}
https://vk.com/foaf.php?id=XXXXXvk.com 
multipart/form-data запроса:
((a,b)=>JSON.stringify(a).match(new RegExp('(?<="'+b+'":")[^"]+')).pop())({
"mass1": [
{
"name1": "value1",
"name2": "value2"
},
{
"name3": "value3",
"name4": "value4"
},
{
"name5": "value5",
"name6": "value6"
}
],
"mass2": [
{
"name7": "value7",
"name8": "value8"
},
{
"name9": "value9",
"name10": "value10"
},
{
"name11": "value11",
"name12": "value12"
}
],
"mass3": [
{
"name13": "value13",
"name14": "value14"
},
{
"name15": "value15",
"name16": "value16"
},
{
"name17": "value17",
"name18": "value18"
}
]
},'name8')
async function primer() {
var testDataVal = await $.ajax({
url: 'https://site.com/script.php',
method: 'POST',
dataType: 'JSON',
data: { text: 'test' }
});
console.log(testDataVal);
}
primer(); // Запускаем пример
