Array to string conversion in Error - php

Question

$keyNames = array();
$keyVals = array();
foreach ($varArray as $key => $name) {
$keyNames .= $key . ', ';
}
foreach ($varArray as $key => $val) {
$keyVals .= '\'' . $val. '\', ';
}
// build query
$sql = "INSERT INTO Organizations (";
$sql .= rtrim($keyNames, ", ");
$sql .= ") VALUES (";
$sql .= rtrim($keyVals, ", ");
$sql .= ");";
echo "<div style=\"padding:5px;background-color:#efefef\">".$sql."</div>"; // this output is working
I am trying to get the above code to work without error. IT currently works but I am getting " Array to string conversion in" error even though I am getting the result that I am expecting.
I am trying to build an sql query from array elements. Both loops throw an error but the echo SQL is giving me what I want. I just want to get rid of the error. I have tried (string) and (array) and implode() and join() but I have not been able to clear the error.
Can you point me in the right direction?

Answer 1

Your procedure seems quite useles because there is implode function for merging array's elements:
$keyNames = implode(',', array_keys($varArray));
$keyValues = '"' . implode('","', $varArray) . '"';
And SQL:
$sql = 'INSERT INTO Organizations (' . $keyNames . ') VALUES (' . $keyValues . ')';

Answer 2

The error is because you're initializing the variables as arrays, and then concatenating strings to them. What you want is:
$keyNames = implode(', ', array_keys($varArray));
$keyVals = implode(', ', array_map(function($val) {
return "'$val'";
}, array_values($varArray)));

Answer 3

The error comes from trying to concatenate a string onto an array. Because you are using $keyNames and $keyValues strictly as strings, there is no need to initialize them as arrays - simply use strings and the error will go away.
Change
$keyNames = array();
$keyVals = array();
to
$keyNames = $keyVals = '';