isset() or empty() statements not giving desired results - php

Question

I am using the following code which is giving the same result irrespective of the condition;
foreach($data as $row)
{
$a = $row['name']; //Here I am calling name from an api
if(empty($a))
{
$a = 'AAA'; // Checking if a$ = $row['']; i.e. 'name' does not exist
}
echo $a;
}
The problem is when $row['name'] has value, it is getting echoed via $a, but if $row['name'] does not exist, I am getting error as undefined index: (probably for since 'name' is not available for that row.)
How to get $a echoed as 'AAA' in case $row['name'] does not exist?

Answer 1

Try checking the actual array and not the declaration of the null.
if(!isset($row['name']))
$a = "AAAA";
https://ideone.com/RuqOBs
The difference is subtle but important :
isset — Determine if a variable is set and is not NULL
empty — Determine whether a variable is empty
is_null — Finds whether a variable is NULL

Answer 2

write the else part like this :
foreach($data as $row){
if(empty($row['name']) || ! isset($row['name']) )
{
$a = 'AAA';}
}
else
{
$a = $row['name'];
}
echo $a;
}
isset() checks if a variable has a value including ( False , 0 , or empty string) , but not NULL. Returns TRUE if var exists; FALSE otherwise.
On the other hand the empty() function checks if the variable has an empty value empty string , 0, NULL ,or False. Returns FALSE if var has a non-empty and non-zero value.

Answer 3

Check to see if name is set before doing your test and combine then into a single statement.
$a = (isset($row['name']) ? $row['name'] : 'AAA');
echo $a;

Answer 4

There are three functions to choose from, which have the following differences:
array_key_exists($key, $array)
This will check if the key exists in the array. If it does, no matter what value is stored behind it (even null), it will return true, false oterhwise.
isset($array[$key])
This will check if the key in the array exists and if the value behind it is not null. If it exists and is not null it will return true, false oterhwise.
empty($array[$key])
This will check if the key exists and if the value behind it is falsy. If it does not exist or the value is falsy (For example null, false, '' or 0) it will return true, false otherwise.
All those functions have in common, that you call them on the array directly. For you, you could call it like this:
foreach($data as $row) {
echo array_key_exists('name', $row) ? $row['name'] : 'AAA';
}
You can exchange array_key_exists('name', $row) with any of the other two functions, depending of what kind of behavior you want.