Php - Can I ignore/skip empty strings when using join() - php

I have a PHP script that shall generate a joined string based on a couple of substrings.
As an example I have provided some sample code below that takes an array of first, middle and last name and adds a linebreak between these in the join function.
The second array contains one empty string (middle name) and I want to ignore it during the join.
I would like to find a solution where I can ignore empty strings in the join() function.
Can it be done with some neat "trick", or do I have to filter the array from empty strings first?
// The array is designed as [firstname, middlename, lastname]
$names1 = array("John", "William", "Smith");
$names2 = array("Adam", "", "Johnson");
echo join("<br>", $names1);
echo "<br>";
echo join("<br>", $names2);
// Result:
/*
John
William
Smith
Adam
<-- Can this empty line be ignored by some "trick"? :)
Johnson
NB. My array in the real situation contains conditions that shall be separatade by the " AND " keyword. I want to avoid results as "condition1 AND AND condition3"

Simply filter out empty array items:
echo join('<br>', array_filter($names2, 'strlen'));

Expanding on Mike's answer and taken directly from php.net
// removes all NULL, FALSE and Empty Strings but leaves 0 (zero) values
$result = array_filter( $array, 'strlen' );

Related

PHP count instances of array items in a string

In PHP 7.3:
Given this array of low relevancy keywords...
$low_relevancy_keys = array('guitar','bass');
and these possible strings...
$keywords_db = "red white"; // desired result 0
$keywords_db = "red bass"; // desired result 1
$keywords_db = "red guitar"; // desired result 1
$keywords_db = "bass guitar"; // desired result 2
I need to know the number of matches as described above. A tedious way is to convert the string to a new array ($keywords_db_array), loop through $keywords_db_array, and then loop through $low_relevancy_keys while incrementing a count of matches. Is there a more direct method in PHP?
The way you described in your question but using array_* functions:
echo count(array_intersect(explode(' ', $keywords_db), $low_relevancy_keys));
(note that you can replace explode with preg_split if you need to be more flexible)
or using preg_match_all (that returns the number of matches):
$pattern = '~\b' . implode('\b|\b', $low_relevancy_keys) . '\b~';
echo preg_match_all($pattern, $keywords_db);
demo

How to implode a multi-dimensional array?

I have an array of arrays like:
$array = [["1.","COTV_LITE(1800)"],["2.","COTV_PREMIUM(2200)"]]
Now, I want to implode this array such that it would return something like this:
COTV_LITE(1800)
COTV_PREMIUM(2200)
How do I achieve this? Calling just the implode() function did not work:
implode ('<br>', $array);
You can call array_map() to implode the nested arrays:
echo implode('<br>', array_map(function($a) { return implode(' ', $a); }, $array));
DEMO
output:
1. COTV_LITE(1800)<br>2. COTV_PREMIUM(2200)
You can use variable length arguments variadic in PHP >= 5.6
Option1
$items = [["1.","COTV_LITE(1800)"],["2.","COTV_PREMIUM(2200)"]];
echo implode(' ',array_merge(...$items));
Output
1. COTV_LITE(1800) 2. COTV_PREMIUM(2200)
This is more of a precursor for the next option.
Option2
If you want to get a bit more creative you can use preg_replace too:
$items = [["1.","COTV_LITE(1800)"],["2.","COTV_PREMIUM(2200)"]];
$replace = [
'/^(\d+\.)$/' => '<li>\1 ',
'/^(\w+\(\d+\))$/' => '\1</li>'
];
echo '<ul>'.implode(preg_replace(array_keys($replace),$replace,array_merge(...$items))).'</ul>';
Output
<ul><li>1. COTV_LITE(1800)</li><li>2. COTV_PREMIUM(2200)</li></ul>
Option3
And lastly using an olordered list, which does the numbers for you. In this case we only need the second item from the array (index 1):
$items = [["1.","COTV_LITE(1800)"],["2.","COTV_PREMIUM(2200)"]];
echo '<ol><li>'.implode('</li><li>',array_column($items,1)).'</li></ol>';
Output
<ol><li>COTV_LITE(1800)</li><li>COTV_PREMIUM(2200)</li></ol>
Personally, I would put it in the ol that way you don't have to worry about the order of the numbers, you can let HTML + CSS handle them. Also it's probably the easiest and most semantically correct way, But I don't know if the numbering in the array has any special meaning or not.
In any case I would most definitely put this into a list to render it to HTML. This will give you a lot more options for styling it, later.
Update
want to use option 1. But how do I put each option on a different line using <br>
That one will put the <br> between each array element:
echo implode('<br>',array_merge(...$items));
Output
1.<br>COTV_LITE(1800)<br>2.<br>COTV_PREMIUM(2200)
The only way to easily fix that (while keeping the array_merge) is with preg_replace, which is the second one. So I will call this:
Option 1.2
$items = [["1.","COTV_LITE(1800)"],["2.","COTV_PREMIUM(2200)"]];
echo implode(preg_replace('/^(\w+\(\d+\))$/',' \1<br>',array_merge(...$items)));
Output
1. COTV_LITE(1800)<br>2. COTV_PREMIUM(2200)<br>
Sandbox
Basically there is no way to tell where the end item is after merging them. That operation effectively flattens the array out and gives us something like this:
["1.","COTV_LITE(1800)","2.","COTV_PREMIUM(2200)"]
So that Regex does this 'COTV_PREMIUM(2200)' becomes ' COTV_PREMIUM(2200)<br>'. This is just a way of changing that without having to dip into the array with some logic or something. WE wind up with this modification to the array:
["1."," COTV_LITE(1800)<br>","2."," COTV_PREMIUM(2200)<br>"]
Then with implode we just flatten it again into a string:
"1. COTV_LITE(1800)<br>2. COTV_PREMIUM(2200)<br>"
The Regex ^(\w+\(\d+\))$
^ - Match start of string
(...) - capture group 1
\w+ - match any working character a-zA-Z0-9_ one or more, eg. COTV_PREMIUM
\( - match the ( literally
\d+ - match digits 0-9 one or more, eg 2200
\) - match the ) literally
$ - match end of string
So this matches the pattern of the second (or even) items in the array, then we replace that with this:
The Replacement ' \1<br>'
{space} - adds a leading space
\1 - the value of capture group 1 (from above)
<br> - append a line break
Hope that makes sense. This should work as long as they meet that pattern. Obviously we can adjust the pattern, but with such a small sample size it's hard for me to know what variations will be there.
For example something as simple as (.+\))$ will work TestIt. This one just looks for the ending ). We just need somethng to capture all of the even ones, while not matching the odd. Regular expressions can be very confusing the first few times you see them, but they are extremely powerful.
PS - I added a few links to the function names, these go the the PHP documentation page for them.
Cheers!
Try this
$items = [["1.","COTV_LITE(1800)"],["2.","COTV_PREMIUM(2200)"]];
$imploded = [];
foreach($items as $item) {
$item_entry = implode(' ', $item);
echo $item_entry . '<br/>'; // display items
$imploded[] = $item_entry;
}
// your desired result is in $imploded variable for further use

How to get a expression inside parentheses and commas inside a string (regex/PHP)

I think my question is so easy to be solved, but I can't.
I want to take this words inside of my query string:
$string = "INSERT INTO table (a,b) VALUES ('foo', 'bar')";
Expected result:
array one = [a,b]
array two = [foo, bar]
There are many regex strategies you could use for this depending on how flexible you need it to be. Here is one very simple implementation which assumes that you know the string 'VALUES' is in all caps, and there is exactly one space before and after 'VALUES' and the two sets of parenthesis.
$string = "INSERT INTO table (a,b) VALUES ('foo', 'bar')";
$matches = array();
// we escape literal parenthesis in the regex, and also add
// grouping parenthesis to capture the sections we're interested in
preg_match('/\((.*)\) VALUES \((.*)\)/', $string, $matches);
// make sure the matches you expect to be found are populated
// before referencing their array indices. index 0 is the match of
// our entire regex, indices 1 and 2 are our two sets of parens
if (!empty($matches[1]) && !empty($matches[2]) {
$column_names = explode(',', $matches[1]); // array of db column names
$values = explode(',', $matches[2]); // array of values
// you still have some clean-up work to do here on the data in those arrays.
// for instance there may be empty spaces that need to be trimmed from
// beginning/ending of some of the strings, and any of the values that were
// quoted need the quotation marks removed.
}
This is only a starting point, be sure to test it on your data and revise the regex as needed!
I recommend using a regex tester to test your regex string against actual query strings you need it to work on. http://regexpal.com/ (There are many others)

preg_match just returns 'Array'?

when using this code to fetch data from http://www.ea.com/uk/football/profile/Calfreezy/360 the code just echo's back the word 'Array'
Here is the code I'm using currently:
<?php
$content = file_get_contents("http://www.ea.com/uk/football/profile/Calfreezy/360");
preg_match('#<div class="stat">Titles Won<span>([0-9\.]*)<span class="sprite13 goalImage cup"></span></span>#', $content, $titleswon);
echo 'Titles Won: '.$titleswon.'';
?>
And this is the HTML I am trying to pull from the url:
<div class="stat">
Titles Won <span>0<span class="sprite13 goalImage cup"></span></span>
</div>
This is just returning Titles won: Array
When if working it should return Titles won: 0
What am I doing wrong, thanks.
You are printing the entire matches array instead of selecting the index(es) that you want from it and printing them.
See the documentation
If matches is provided, then it is filled with the results of search. $matches[0] will contain the text that matched the full pattern, $matches[1] will have the text that matched the first captured parenthesized subpattern, and so on.
preg_match() produces an array of matches. If you print out an array in string context, you get Array as the text. e.g.
$arr = array('foo' => 'bar');
echo $arr; // prints "Array"
echo $arr['foo']; // prints "bar"
preg_match returns an array as can be seen from the documentation.
if you want to see all the contents of the array use
var_dump( $titleswon );
If you just need the matched, you have to address that specific part.
The best approach would be :
if (preg_match('#<div class="stat">Titles Won<span>([0-9\.]*)<span class="sprite13 goalImage cup"></span></span>#', $content, $titleswon)) {
echo 'Titles Won: '.$titleswon[1].'';
}
The third param tho preg_match is passed by reference and will contain an array with matches in every capture group. You are using two "groups". The whole match and ([0-9\.]*) which will be the second. So I expect you need this:
echo 'Titles Won: '.$titleswon[1].''; // note the array is indexed by 0
If you have a look to the preg_match documentation:
http://php.net/manual/en/function.preg-match.php
You can see that in the $match argument is actually an array, $match[0] containing the whole match, and the consecutive array elements containing the subqueries.
If you do var_dump($titleswon) or print_r($titleswon) you will see the whole information, then you can access to the desired info, in your case it would be $titleswon[1]

Replace text within brackets with thus-named variable in PHP

I want to replace all strings in square brackets ([]) with a randomly chosen item from an array that's named that string.
It's very similar to this issue, but with a twist, in that I want to replace different brackets' contents with strings from arrays named that.
An example should make this a bit clearer.
So say I've got the string
"This is a very [adjective] [noun], and this is a [adjective] [noun]."
And the variables:
$adjective = array("big","small","good","bad");
$noun = array("house","dog","car");
And we want it to return "This is a very big house, and this is a good dog." or whatever, by choosing randomly. That is, I want to write a PHP function that will replace each [string] with a randomly chosen item from the array named $string. For now it doesn't matter if by randomly choosing it ends up repeating choices, but it must make a fresh choice for each [] item.
I hope I've explained this clearly. If you get what I'm trying to achieve and can think of a better way to do it I'd be very grateful.
Algorithm
Match for this regex: (\[.*?\])
For each match group pick an item from the related array.
Replace in string by order.
Implementation
$string = "This is a very [adjective] [noun], and this is a [adjective] [noun].";
$adjective = array("big","small","good","bad");
$noun = array("house","dog","car");
// find matches against the regex and replaces them the callback function.
$result = preg_replace_callback(
// Matches parts to be replaced: '[adjective]', '[noun]'
'/(\[.*?\])/',
// Callback function. Use 'use()' or define arrays as 'global'
function($matches) use ($adjective, $noun) {
// Remove square brackets from the match
// then use it as variable name
$array = ${trim($matches[1],"[]")};
// Pick an item from the related array whichever.
return $array[array_rand($array)];
},
// Input string to search in.
$string
);
print $result;
Explanation
preg_replace_callback function performs a regular expression search and replace using provided callback function.
First parameter is regular expression to match (enclosed between slashes): /(\[.*?\])/
Second parameter is callback function to call for each match. Takes the current match as parameter.
We have to use use() here to access the arrays from inside the function, or define the arrays as global: global $adjective = .... Namely, we have to do one of the followings:
a) Define arrays as global:
...
global $adjective = array("big","small","good","bad");
global $noun = array("house","dog","car");
...
function($matches) {
...
b) Use use:
...
$adjective = array("big","small","good","bad");
$noun = array("house","dog","car");
...
function($matches) use ($adjective, $noun) {
...
First line of the callback function:
trim: Removes square brackets ([]) from the match using trim function.
${}: Creates a variable to use as array name with the match name. For example, if the $match is [noun] then trim($matches[1],"[]") returns noun (without brackets) and ${noun} becomes the array name: $noun. For more information on the topic, see variable variables.
Second line randomly picks an index number available for the $array and then returns the element at this position.
Third parameter is the input string.
The code below will do the work:
$string = "This is a very [adjective] [noun], and this is a [adjective] [noun]."
function replace_word ( $matches )
{
$replaces = array(
'[adjective]' => array("big", "small", "good", "bad"),
'[noun]' => array("house", "dog", "car")
);
return $replaces[$matches[0]][array_rand($replaces[ $matches[0] ])];
}
echo preg_replace_callback("(\[.*?\])", "replace_word", $string);
First, we regular expression match on the [something] parts of the word, and call the replace_word() callback function on it with preg_replace_callback(). This function has an internal $replaces two dimension deep array defined inside, each row defined in a [word type] => array('rep1', 'rep2', ...) format.
The tricky and a bit obfuscated line is the return $replaces[$matches[0]][array_rand($replaces[ $matches[0] ])];. If I chunk it down a bit, it'll be a lot more parsable for you:
$random = array_rand( $replaces[ $matches[0] ] );
$matches[0] is the word type, this is the key in the $replaces array we are searching for. This was found by regular expression in the original string. array_rand() basically selects one element of the array, and returns its numerical index. So $random right now is an integer somewhere between 0 and the (number of elements - 1) of the array containing the replaces.
return $replaces[ $matches[0] ][$random];
This will return the $randomth element from the replace array. In the code snippet, these two lines are put together into one line.
Showing one element only once
If you want disjunct elements (no two adjective or noun repeated twice), then you will need to do another trick. We will set the $replaces array to be defined not inside the replace_word() function, but outside it.
$GLOBALS['replaces'] = array(
'[adjective]' => array("big", "small", "good", "bad"),
'[noun]' => array("house", "dog", "car")
);
Inside the function, we will set the local $replaces variable to be a reference to the newly set array, with calling $replaces = &$GLOBALS['replaces'];. (The & operator sets it a reference, so everything we do with $replaces (remove and add elements, for example) modifies the original array too. Without it, it would only be a copy.)
And before arriving on the return line, we call unset() on the currently to-be-returned key.
unset($replaces[$matches[0]][array_rand($replaces[ $matches[0] ])]);
The function put together now looks like this:
function replace_word ( $matches )
{
$replaces = &$GLOBALS['replaces'];
unset($replaces[$matches[0]][array_rand($replaces[ $matches[0] ])]);
return $replaces[$matches[0]][array_rand($replaces[ $matches[0] ])];
}
And because $replaces is a reference to the global, the unset() updates the original array too. The next calling of replace_word() will not find the same replace again.
Be careful with the size of the array!
Strings containing more replace variables than the amount of replace values present will throw an Undefined index E_NOTICE. The following string won't work:
$string = "This is a very [adjective] [noun], and this is a [adjective] [noun]. This is also an [adjective] [noun] with an [adjective] [noun].";
One of the outputs look like the following, showing that we ran out of possible replaces:
This is a very big house, and this is a big house. This is also an small with an .
Another good (easier) method of doing this (not my solution)
https://stackoverflow.com/a/15773754/2183699
Using a foreach to check on which variables you want to replace and replacing them with
str_replace();
You can use preg_match and str_replace function to achive this goal.
First find the matches using preg_match function and then create search & replace array from the result.
Call str_replace function by passing the previous arrays as parameters.
This is my minor update to mmdemirbas' answer above. It lets you set the variables outside of the function (i.e. use globals, as said).
$result = preg_replace_callback(
// Matches parts to be replaced: '[adjective]', '[noun]'
'/(\[.*?\])/',
// Callback function. Use 'use()' or define arrays as 'global'
function($matches) use ($adjective, $noun) {
// Remove square brackets from the match
// then use it as variable name
$arrayname = trim($matches[1],"[]");
$array = $GLOBALS[$arrayname];
// Pick an item from the related array whichever.
return $array[array_rand($array)];
},
// Input string to search in.
$string
);
print $result;

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