I'm wanting to make a PHP array and use people's names as keys mapping to employee ID numbers. Example:
$staffID = array(
"Doe, Jane" => 124,
"Smith, John" => 876
);
I'd like to keep them LastName, FirstName so that I can easily peruse down the list later on. I'm concerned about those commas in the keys though. Is this valid in PHP?
Yes, they're just strings. You can have any valid string (or integer) as an array key.
Also you may use array_search() function
$staffID = array(
124 => 'Doe, Jane',
876 => 'Smith, John'
);
$id = array_search('Smith, John', $staffID);
Related
how to put integer values, taken by another array, instead of 1,2,3 like this?
$arr_id = array(1,2,3); //this arr_id go to line 2 instead of 1,2,3
'id' => array('$in' => array(1,2,3))
well, putting $arr_id instead of "1,2,3"... something like this
'id' => array('$in' => array($arr_id))
the problem is that 1,2,3 are number, but in my $arr_id i've strings. If i try to convert string to int i've a problem with "," too
here
array($arr_id))
i need to have integers (not string) taken by $arr_id, separated by ","...
You can convert a string array to an int array in PHP using:
$arr_id_str = array("1","2","3");
var_dump(array_map('intval',$arr_id_str));
I stuck with a problem: I have an array with IDs and want to assign theses IDs to a key of a associative array:
$newlinkcats = array( 'link_id' => $linkcatarray[0], $linkcatarray[1], $linkcatarray[2]);
this works fine, but I don't know how many entries in $linkcatarray. So I would like to loop or similar. But I don't know how.
no push, cause it is no array
no implode, cause it is no string
no =, cause it overrides the value before
Could anyone help?
Thanks
Jim
Why not just implode it ?
$newlinkcats = array(
'link_id' => implode(
',',
$linkcatarray
)
);
Or just do this:
// Suggested by Tularis
$newlinkcats = array(
'link_id' => $linkcatarray
);
If your $linkcatarray array is only comprised of the values you wish to assign to the link_id key, then you can simply point the key at that array:
$newlinkcats = array('link_id' => $linkcatarray);
If that array contains more values that you don't want included, then take a look at array_slice() to only grab the indexes you need:
// Grabs the first 3 values from $linkcatarray
$newlinkcats = array('link_id' => array_slice($linkcatarray, 0, 3));
If your desired indexes aren't contiguous, it may be easier to cherry-pick them and use a new array:
$newlinkcats = array('link_id' => array(
$linkcatarray[7],
$linkcatarray[13],
$linkcatarray[22],
// ...
));
Let's say I have an array
$array = array(
'username' => "username",
'location' => "location",
'other' => "other");
This array can hold data for many users, so there could be different values for each 'username', 'location', and 'other' fields. How can I use in_array() or another function to determine if a specific username exists in the array already? Because what if a user has a username like "nyc" and a location of "nyc" and I do
in_array("nyc", $array);
How exactly should something like this be approached?
Thank you.
To achieve something that I think is what you want, you can make an array of associative arrays that have the same keys.
<?php
// This syntax will work only on PHP 5.4
$a=[["name"=>"john","age"=>25],["name"=>"philip","age"=>110]];
print_r(array_filter($a, function($item) {return $item["name"] === "john"; }));
?>
Outputs:
Array
(
[0] => Array
(
[name] => john
[age] => 25
)
)
If you just wanted to know if a person named John was in the list, you can just use sizeof/count on the returned array.
This will allow you to have any number of duplicates, and you don't need to specify any keys. Check out the functions: array_filter, array_reduce, array_map. With all of these, you can process your list using closures like in my example above.
Instead of using associative arrays in your array, you could have objects too. Objects are more heavyweight, and need initialization and stuff, so it is grotesque for using them for tiny static (hardcoded) lists. But they may come handy when your data structures grow and you want to make sure every list item has a certain property (the constructor of the class could ensure that everything is initialized). But the good thing is that filter, reduce and map would still work. The "$item" would then be your object.
$users = array( 'user_id' => array('username' => "username",
'location' => "location",
'other' => "other");
user_id is their NUMBER user_id
So you then call $users['####']['username'];
IE:
$users = array( '1' => array('username' => 'Jim',
'location' => 'Florida',
'other' => "other"),
'2' => array('username' => 'Jane',
'location' => 'Maryland',
'other' => "Grapes"));
Then use array_keys() to search for their user_id
$string = "php, photoshop, css";
I'm producing an array from the comma separated values above using the str_getcsv() function:
$array = str_getcsv($string);
Result:
Array ( [0] => php [1] => photoshop [2] => css )
How can I replace the key integers with a string tag for all elements like seen below?
Array ( [tag] => php [tag] => photoshop [tag] => css )
Edit: if not possible what alternative can I apply? I need the array keys to be identical for a dynamic query with multiple OR clauses
e.g.
SELECT * FROM ('posts') WHERE 'tag' LIKE '%php% OR 'tag' LIKE '%photoshop% OR 'tag' LIKE '%css%'
I'm producing the query via a function that uses the array key as a column name and value as criteria.
That is not possible. You can have only one item per key. But in your example, the string "tag" would be the key of every item.
The other way arround would work. So having an array like this:
array('php' => 'tag', 'photoshop' => 'tag', 'css' => 'tag');
This might help you, if you want to save the "type" of each entry in an array. But as all the entries of your array seems to be from the same type, just forget about the "tag" and only store the values in a numeric array.
Or you can use a multidimensional array within the numeric array to save the type:
array(
0 => array( 'type' => 'tag', 'value' => 'php' ),
1 => array( 'type' => 'tag', 'value' => 'photoshop' ),
2 => array( 'type' => 'tag', 'value' => 'css' )
);
But still using just an numeric array should be fine if all the entries have the same type. I can even think of a last one:
array(
'tag' => array('php', 'photoshop', 'css')
);
But even if I repeat myself: Just use an ordinary array and name it something like $tag!
BTW: explode(', ', %string) is the more common function to split a string.
To build SQL statement you might do something like this:
// ... inside you build function
if(is_array($value)){
$sql .= "'".$key."' LIKE '%."implode("%' OR '".$key."' LIKE '%", $value)."%'";
} else {
$sql .= "'".$key."' LIKE '%".$value."%'";
}
This might look confusing but it's much cleaner than runnig into two foreach-loops building the query.
That won't work. Your array keys have to be unique, or subsequent additions will simply overwrite the previous key.
As the others said, keys have to be unique. Otherwise, which element should be returned if you access $arr['tag']? If you now say "all of them", then create a nested array:
$array = array();
$array['tag'] = str_getcsv($string);
The value $array['tag'] will be another array (the one you already have) with numerical keys. This makes, because you have a list of tags and lists can be represented as arrays too.
Understanding arrays is very important if you want to work with PHP, so I suggest to read the array manual.
Assuming you know the size of your array beforehand
$tags = array("tag1","tag2","tag3");
$data = array("php","photoshop","css");
$myarray = array();
for ($i=0; $i<count($data); $i++) {
$myarray[$i] = array($data[$i], $tags[$i]);
}
Then
echo $myarray[0][0] . ", " . $myarray[0][1];
Outputs:
php, tag1
array(
[0]
name => 'joe'
size => 'large'
[1]
name => 'bill'
size => 'small'
)
I think i'm being thick, but to get the attributes of an array element if I know the value of one of the keys, I'm first looping through the elements to find the right one.
foreach($array as $item){
if ($item['name'] == 'joe'){
#operations on $item
}
}
I'm aware that this is probably very poor, but I am fairly new and am looking for a way to access this element directly by value. Or do I need the key?
Thanks,
Brandon
If searching for the exact same array it will work, not it you have other values in it:
<?php
$arr = array(
array('name'=>'joe'),
array('name'=>'bob'));
var_dump(array_search(array('name'=>'bob'),$arr));
//works: int(1)
$arr = array(
array('name'=>'joe','a'=>'b'),
array('name'=>'bob','c'=>'d'));
var_dump(array_search(array('name'=>'bob'),$arr));
//fails: bool(false)
?>
If there are other keys, there is no other way then looping as you already do. If you only need to find them by name, and names are unique, consider using them as keys when you create the array:
<?php
$arr = array(
'joe' => array('name'=>'joe','a'=>'b'),
'bob' => array('name'=>'bob','c'=>'d'));
$arr['joe']['a'] = 'bbb';
?>
Try array_search
$key = array_search('joe', $array);
echo $array[$key];
If you need to do operations on name, and name is unique within your array, this would be better:
array(
'joe'=> 'large',
'bill'=> 'small'
);
With multiple attributes:
array(
'joe'=>array('size'=>'large', 'age'=>32),
'bill'=>array('size'=>'small', 'age'=>43)
);
Though here you might want to consider a more OOP approach.
If you must use a numeric key, look at array_search
You can stick to your for loop. There are not big differences between it and other methods – the array has always to be traversed linearly. That said, you can use these functions to find array pairs with a certain value:
array_search, if you're there's only one element with that value.
array_keys, if there may be more than one.