I want to sum in my array :
<?php
if(isset($values[$key])) {
$values[$key] += $total;
} else {
$values[$key] = $total;
}
If I just write "+=", I have error "Undefined index". Do you know an easier way? Because is too long on a long code. Thanks
You can shorten it a bit
<?php
if(!isset($values[$key]))
$values[$key]= 0;
$values[$key] += $total;
but the way you wrote the code already is a quite succinct and, more importantly, quite clean way.
edit: the error occurs in the first place because when writing
$values[$key] += $total;, internally it is the same as $values[$key] = $values[$key] + $total - and when $value[$key] is not initiated in the first place, it can not be read.
PHP normally assumes that it is 0 then and throws the "key not defined"-note to notificate the programmer that he forgot to initiate an element of the array.
Try this:
<?php
$values[$key] = @$values[$key] + $total;
undefined index error but just omits the error message - which works, but is not really a "clean solution"You can do everything in one line:
$values[$key] = array_key_exists($key, $values) ? $values[$key] + $total : $total;
Here's the reference:
It should be the $total first
<?php
$total = 0;
if(isset($values[$key])) {
$total += $values[$key]; //Also equal to $total = $total + $values[$key];
} else {
$total = $values[$key];
}
Another way to use less lines is to use a ternary operator:
<?php
$values[$key] = isset($values[$key]) ? ($values[$key] + $total) : $total;
I'm not entirely sure what you are trying to do, it would be quite nice to see the array you are passing into this. Either way the undefined index error is being produced because you are trying to access the array key $key when it does not exist.
From what I can work out, you just want to add the total to a key off your array if that key is set? If the key is not set then you want to create that key and set its value equal to the current total. At least that is my understanding of what you want.
So what you have done is almost correct except you try to access an index that hasn't been set when your conditional fails.
if (!isset($array[$key])) {
$array[$key] = $total;
} else {
$array[$key] += $total;
}
The above should fix your error, there probably are a few cleaner solutions but without knowing more information about the contents of the array and the purpose of the script it is hard to say what is the best method to use.
