I have a function that loops through an array and runs database operations within each loop.
function myfunc($array) {
foreach($array as $a) {
// db operations here
echo $a["one"].'<br />';
echo $a["two"].'<br />';
}
}
but then sometimes, I have a single-dimensional array such as
$x = array(
'one' => '1',
'two' => '2'
);
myfunc($x);
however, it's falling to loop because there is nothing to loop over.
I get errors saying:
Warning: Illegal string offset 'one'
Warning: Illegal string offset 'two'
i know I could make the single dimensional array $x[] but that would mean I have to reset it to empty each time ($x = array();) - which isn't a problem but if it;s possible to loop over a single dimensional array, i'd rather do that
If you know you have only one entry, you'll want to wrap it into a array of one, like this:
myfunc([$array]);
Related
I am a noob attempting to solve a program for a word search app I am doing. My goal is to take a string and compare how many times each letter of that string appears in another string. Then put that information into an array of key value pairs, where the key is each letter of the first string and the value is the number of times. Then order it with ar(sort) and finally echo out the value of the letter that appears the most (so the key with the highest value).
So it would be something like array('t' => 4, 'k' => '9', 'n' => 55), echo the value of 'n'. Thank you.
This is what I have so far that is incomplete.
<?php
$i = array();
$testString= "endlessstringofletters";
$testStringArray = str_split($testString);
$longerTestString= "alphabetalphabbebeetalp
habetalphabetbealphhabeabetalphabetalphabetalphbebe
abetalphabetalphabetbetabetalphabebetalphabetalphab
etalphtalptalphabetalphabetalbephabetalphabetbetetalphabet";
foreach ($testStringArray AS $test) {
$value = substr_count($longerTestString, $testStringArray );
/* Instead of the results of this echo, I want each $value to be matched with each member of the $testStringArray and stored in an array. */
echo $test. $value;
}
/* I tried something like this outside of the foreach and it didn't work as intended */
$i = array_combine($testStringArray , $value);
print_r($i);
If I understand correctly what you are after, then it's as simple as this:
<?php
$shorterString= "abc";
$longerString= "abccbaabaaacccb";
// Split the short sring into an array of its charachters
$stringCharachters = str_split($shorterString);
// Array to hold the results
$resultsArray = array();
// Loop through every charachter and get their number of occurences
foreach ($stringCharachters as $charachter) {
$resultsArray[$charachter] = substr_count($longerString,$charachter);
}
print_r($resultsArray);
Suppose I've got the following string:
) [6] => Array ( [2014-05-05 00:0] => My actual content
If I want to only be left with My actual content at the end, what is the best way to split the entire string?
Note: the words My actual content are and can change. I'm hoping to cut the string based on the second => string as this will be present at all times.
It seems you're just looking to find the first value of an array with keys you do not know. This is super simple:
Consider the following array:
$array = array(
'2014-05-22 13:36:00' => 'foo',
'raboof' => 'eh',
'qwerty' => 'value',
'8838277277272' => 'test'
);
Method #1:
Will reset the array pointer to the first element and return it.
Using reset:
var_dump( reset($array) ); //string(3) "foo"
DEMO
Method #2:
Will reset the entire array to use keys of 0, 1, 2, 3...etc. Useful if you need to get more than one value.
Using array_values:
$array = array_values($array);
var_dump( $array[0] ); //string(3) "foo"
DEMO
Method #2.5:
Will reset the entire array to use keys of 0, 1, 2, 3...etc and select the first one into the $content variable. Useful if you need to get more than one value into variables straight away.
Using list and array_values:
list( $content ) = array_values($array);
var_dump( $content ); //string(3) "foo"
DEMO
Method #3:
Arrays are iteratable, so you could iterate through it but break out immediately after the first value.
Using a foreach loop but break immediatly:
foreach ($array as $value) {
$content = $value;
break;
}
var_dump($content); //string(3) "foo"
DEMO
To Answer your question, on extracting from a string based on last 'needle'...
Okay, this is quite an arbitrary question, since it seems like you're showing us the results from a print_r(), and you could reference the array key to get the result.
However, you mentioned "... at the end", so I'm assuming My actual content is actually right at the end of your "String".
In which case there's a very simple solution. You could use: strrchr from the PHP manual - http://www.php.net/manual/en/function.strrchr.php.
So you're looking at this: strrchr($string, '=>');
Hope this answers your question. Advise otherwise if not please.
you have to use foreach loop in a foreach to get the multi dimentional array values.
foreach($value as $key){
foreach($key as $val){
echo $val;
}
}
I'm just wondering about how variable variables that point to Arrays handle. Take the code below:
$a = new stdClass();
$a->b = array('start' => 2);
$c = 'b';
$d = 'start';
print $a->$c; // => Array
print $a->$c['start']; // => Array
print $a->$c[0]; // => Array
print $a->$c[0][0]; //=> PHP Fatal error: Cannot use string offset as an array in php shell code on line 1
The first print I expect, the second one I don't, or the 3rd. The 4th is expected after realizing that the evaluation of $a->$c is apparently a string. But then why does this work:
$t = $a->$c;
print $t['start']; //=> 2
I'm asking more because I'm curious than I need to know how to nicely do
$e = 'start';
$a->$c[$e]
Anyone know why I can't index directly into the array returned by the variable variable usage?
It comes down to order of operations and how PHP type juggles. Hint: var_dump is your friend, echo always casts to a string so it is the worst operation for analyzing variable values, esp in debug settings.
Consider the following:
var_dump($a->$c); // array (size=1) / 'start' => int 2
var_dump($a->$c['start']); // array (size=1) / 'start' => int 2
var_dump($a->b['start']); // int 2
var_dump($c['start']); // string 'b' (length=1)
The key here is how PHP interprets the part of $c['start'] (include $c[0] here as well). $c is the string 'b', and when attempting to get the 'start' index of string 'b' this simply returns the first character in the string, which happens to simply be the only letter (b) in the string. You can test this out by using $c = 'bcdefg'; - it'll yield the same result (in this specific case). Also, $c['bogus'] will yield the exact same thing as $c['start']; food for thought, and make sure you do the required reading I linked to.
So with this in mind (knowing that $c['start'] reluctantly returns 'b'), the expression $a->$c['start'] is interpreted at $a->b. That is, the order is $a->($c['start']) and not ($a->$c)['start'].
Unfortunately you can't use () nor {} to steer the parser (PHP SCREAMs), so you won't be able to accomplish what you want in a single line. The following will work:
$e = 'start';
$interim = $a->$c;
echo $interim[$e];
Alternatively, you can cast your arrays as objects (if you have the luxury):
$a->$c = (object) $a->$c; // mutate
var_dump($a->$c->$e);
$interim = (object) $a->$c; // clone
var_dump($interim->$e);
...by the way, referring back up to $c['start'] and $c[0], in regards to $c[0][0] you simply can't do this because $c[0] is the character b in string 'b'; when access the character/byte b it will not have a property of [0].
$a->$c[0]; is actually equal to: array('start' => 0)
so when you did:
print $a->$c[0][0];
You are trying to load an array element from $a->$c[0] at index 0 which does not exists.
however, this will work:
print $a->$c[0]['start'];
I am facing a problem that undefined offset :1 in line 3. I can't understand that what type of error it is.
Can anyone tell me that why such error occurs in php
Undefined offset in line : 3
foreach ($lines as $line)
{
list($var,$value) = explode('=', $line); //line 3
$data[$var] = $value;
}
Your are getting PHP notice because you are trying to access an array index which is not set.
list($var,$value) = explode('=', $line);
The above line explodes the string $line with = and assign 0th value in $var and 1st value in $value. The issue arises when $line contains some string without =.
I know this an old question and the answer provided is sufficient.
Your are getting PHP notice because you are trying to access an array
index which is not set.
But I believe the best way to overcome the problem with undefined indexes when there are cases where you may have an empty array using the list()/explode() combo is to set default values using array_pad().
The reason being is when you use list() you know the number of variables you want from the array.
For example:
$delim = '=';
$aArray = array()
$intNumberOfListItems = 2;
list($value1, $value2) = array_pad(explode($delim, $aArray, $intNumberOfListItems ), $intNumberOfListItems , null);
Essentially you pass a third parameter to explode stating how many values you need for your list() variables (in the above example two). Then you use array_pad() to give a default value (in the above example null) when the array does not contain a value for the list variable.
This is caused because your $line doesn't contain "=" anywhere in the string so it contains only one element in array.list() is used to assign a list of variables in one operation. Your list contains 2 elements but as from data returned by implode, there is only one data. So it throws a notice.
A way to overcome that is to use array_pad() method.
list($var,$value) = array_pad(explode('=', $line),2,null);
by doing list($var, $value) php will expect an array of 2 elements, if the explode function doesn't find an equal symbol it will only return an array with 1 element causing the undefined offset error, offset 1 is the second element of an array so most likely one of your $line variables doesn't have an equal sign
This is due to the array. The array index is not showing due to this undefine offset error will come...
So please check the array with print_r function.
The list language construct is used to create individual variables from an array. If your array doesn't have enough elements for the number of variables you are expecting in the list call, you will get an error. In your case you have 2 variables so you need an array with 2 items - indexes 0 and 1.
http://php.net/manual/en/function.list.php
Solution:
$lines = array('one' => 'fruit=apple', 'two' => 'color=red', 'three' => 'language');
foreach ($lines as $line)
{
list($var,$value) = (strstr($line, '=') ? explode('=', $line) : array($line, ''));
$data[$var] = $value;
}
print_r($data);
Try this one..
For reference
http://in1.php.net/manual/en/function.list.php
http://in1.php.net/manual/en/function.explode.php
Ok, so I need to grab the position of 'blah' within this array (position will not always be the same). For example:
$array = (
'a' => $some_content,
'b' => $more_content,
'c' => array($content),
'blah' => array($stuff),
'd' => $info,
'e' => $more_info,
);
So, I would like to be able to return the number of where the 'blah' key is located at within the array. In this scenario, it should return 3. How can I do this quickly? And without affecting the $array array at all.
$i = array_search('blah', array_keys($array));
If you know the key exists:
PHP 5.4 (Demo):
echo array_flip(array_keys($array))['blah'];
PHP 5.3:
$keys = array_flip(array_keys($array));
echo $keys['blah'];
If you don't know the key exists, you can check with isset:
$keys = array_flip(array_keys($array));
echo isset($keys['blah']) ? $keys['blah'] : 'not found' ;
This is merely like array_search but makes use of the map that exists already inside any array. I can't say if it's really better than array_search, this might depend on the scenario, so just another alternative.
$keys=array_keys($array); will give you an array containing the keys of $array
So, array_search('blah', $keys); will give you the index of blah in $keys and therefore, $array
User array_search (doc). Namely, `$index = array_search('blah', $array)