- json_encode: documentation ( source)
<?php
$arr1 = ["1st Desc","2nd Desc","3rd Desc"];
$arr2 =["100.10","10.50","39.99"];
$expected = [];
foreach($arr1 as $k=>$v){
$expected[$k] = ['description'=>$v,'amount'=>$arr2[$k]];
}
echo json_encode($expected,JSON_PRETTY_PRINT);
?>