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phpimplodenotnull

Formatting php echo with null values

Let's say I have a php array called $t with 5 elements in it. For demonstration purposes, let's call it $t = [a,b,c,d,e].

I want to echo all elements in parenthesis like this: (a, b, c, d, e). However, I want this parenthesis format to hold if there are null values in the array $t.

For example, if c and d are null in the array, it should echo (a, b, e). What's an efficient way of doing this without trying every possible permutation (impossible with large array sizes).

I have tried: 

echo "("   
for($j=0; $j<5; $j++){
    if(!empty($t[j])){
        echo " $t[j], ";
    }
}
echo ")"

But this leaves a comma at the end, and even then I'm not sure if it accounts for every possible case. Thanks in advance!

Solution

  • This works pretty well:

    <?php

function is_not_null($v) { return !is_null($v); }
$t = ['a', 'b', null, null, 'e'];
echo '('.implode(',', array_filter($t, 'is_not_null')).')';

    Result:

    (a,b,e)