Question

How to check if key exists in array with PHP

Answer 1

$user = [
    'fname' => 'Jennifer',
    'age' => 45
];

if (array_key_exists('fname', $user))
    echo "true";


 
/*
run: 

true
  
*/ 

 

Cleaner teeth, healthier you!
Get The Secret to a Bright and Healthy Smile

Answer 2

$user = [
    'fname' => 'Jennifer',
    'age' => 45
];

if (isset($user['fname']))
    echo "true";


 
/*
run: 

true
  
*/ 

 

Cleaner teeth, healthier you!
Get The Secret to a Bright and Healthy Smile

Answer 3

$user = [
    'fname' => 'Jennifer',
    'age' => 45
];

if (!empty($user['fname']))
    echo "true";


 
/*
run: 

true
  
*/ 

 

Cleaner teeth, healthier you!
Get The Secret to a Bright and Healthy Smile

Answer 4

$user = [
    'fname' => 'Jennifer',
    'age' => 45,
    'test' => null
];

if (!empty($user['test']))
    echo "true";
else
    echo "false";


 
/*
run: 

false
  
*/ 

 

Cleaner teeth, healthier you!
Get The Secret to a Bright and Healthy Smile

Answer 5

$user = [
    'fname' => 'Jennifer',
    'age' => 45,
    'test' => null
];

if (isset($user['test']))
    echo "true";
else
    echo "false";


 
/*
run: 

false
  
*/ 

 

Cleaner teeth, healthier you!
Get The Secret to a Bright and Healthy Smile

Answer 6

$user = [
    'fname' => 'Jennifer',
    'age' => 45,
    'test' => null
];

if (array_key_exists('test', $user))
    echo "true";
else
    echo "false";


 
/*
run: 

true
  
*/  

 

Cleaner teeth, healthier you!
Get The Secret to a Bright and Healthy Smile