使用PHP中另一个数组的值替换数组中的值

Question

I have two arrays. Array 1 is a mapping between DeptID and dept_number:

array(66) {
[0] => array(2) {
 'DeptID' → str•4 '1300'
 'dept_number' → str•3 '18'
}

[1] => array(2) {
 'DeptID' → str•4 '1000'
 'dept_number' → str•3 '129'
}

[2] => array(2) {
 'DeptID' → str•4 '2400'
 'dept_number' → str•3 '101'
}

...and so on

Array 2 has store records which include dept_number. I want to replace the dept_number value with the DeptID value from Array 1.

array(27) {
[0] => array(11) {
 'org_id' → str•2 '11'
 'org_number' → str•2 '11'
 'supplier_number' → str•4 '3806'
 'supplier_name' → str•17 'TEST1'
 'invoice_number' → str•8 'DXXX'
 'receive_date' → str•10 '2013-09-11'
 'inv_status' → str•7 'Pending'
 'final_cost' → str•6 '317.30'
 'final_qty' → str•5 '12.00'
 'dept_number' → str•2 '18'
 'dept_descr' → str•10 'BULK 1'
}

[1] => array(11) {
 'org_id' → str•2 '11'
 'org_number' → str•2 '11'
 'supplier_number' → str•4 '1070'
 'supplier_name' → str•24 'TEST2'
 'invoice_number' → str•7 'DXXY'
 'receive_date' → str•10 '2013-09-11'
 'inv_status' → str•7 'Pending'
 'final_cost' → str•6 '830.30'
 'final_qty' → str•5 '26.00'
 'dept_number' → str•2 '101'
 'dept_descr' → str•10 'BULK 2'
}

...and so on

How do I replace the dept_number in Array 2 with the DeptID from Array 1?

Answer 1

Hash tables.

Start making a KVP (Key Value Pair) array of your mapping array with the key being whatever value you want to look up values for (in this case, dept_number) and set the value of the array key to DeptID:

$deptKVP = array();
foreach ($deptMappings as $deptMapping) {
    $deptKVP[$deptMapping['dept_number']] = $deptMapping['DeptID'];
}

/*
    $deptKVP = [
        18 => 1300,
        129 => 1000,
        101 => 2400
    ];
*/

And then simply iterate through your regular array:

foreach ($array2 as &$subArray) {
    $subArray['dept_number'] = $deptKVP[$subArray['dept_number']];
}
unset($subArray); //Unset the reference