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So, basically I'm trying to count the number of landline phone numbers in a list of both landlines and mobile phone numbers $mobile_list (071234567890,02039989435,0781...)
$mobile_array = explode(",",$mobile_list); // turn into an array
$landlines = array_count_values($mobile_array); // create count variable
echo $landlines["020..."]; // print the number of numbers
So, I get the basic count specific elements function, but I don't see where I can specify if an element 'starts with' or 'contains' a sequence. With the above you can only specify an exact phone number (obviously not useful).
Any help would be great!
I don't see any reason to first explode the string to an array, and then check each array item.
That is a complete waste of performance!
I suggest using preg_match_all and match with word boundary "020".
That means the "word" has to start with 020.
$mobile_list = "071234567890,02039989435,0781,020122,123020";
preg_match_all("/\b020\d+\b/", $mobile_list, $m);
var_dump($m);
echo count($m[0]); // 2
https://3v4l.org/ucSDm
The lightest and fastest method I have found is to explode on ",020".
The array that is returned has item 0 as undefined, meaning we don't know if it's a 020 number so I have to look at that manually.
$temp = explode(",020", $mobile_list);
$cnt = count($temp);
if(substr($temp[0],0,3) != "020") $cnt--;
echo $cnt;
A small scale test shows this as the fastest method.
https://3v4l.org/rD54d
You can use array_reduce() to count the occurrences of strings beginning with '020'
$mobile_list = "02039619491,07143502893,02088024526,07351261813,02095694897";
$mobile_array = explode(',', $mobile_list);
function landlineCount($carry, $item)
{
if (substr($item, 0, 3) === '020') {
return $carry += 1;
}
return $carry;
}
$count = array_reduce($mobile_array, 'landlineCount');
echo $count;
prints 3
I'm sure the OP has finished what they needed to do hours ago but for fun here is a faster way to count the landlines.
I hadn't spotted that the question original code was exploding the string.
That isn't necessary, you can just count the sub strings with substr_count() this could miss the first which wouldn't have a comma before it so I check for that too with substr().
If you need the total count of all numbers you can just count the commas with substr_count() again and add one.
$count = substr($mobile_list, 0, 3) === '020' ? 1 : 0;
$count += substr_count($mobile_list, ",020");
$totalCount = substr_count($mobile_list, ",") + 1;
echo $count;
echo $totalCount;
Here is the bench run a 1000 times to get an average.
https://3v4l.org/Sma66
Use array_filter() or preg_grep() functions to find all numbers that contain or starts with given number sequence.
Note: There is easier and better solution in other answers that cover request to find values that start with given number sequence.
Because you have mentioned - "but I don't see where I can specify if an element 'starts with' or 'contains' a sequence." - My code assumes that you wan't to find any occurrence of sequence, not only in start of string of each item.
$mobile_list = '02000, 02032435, 039002300, 00305600';
$mobile_array = explode(",",$mobile_list); // turn into an array
$landlines = array_count_values($mobile_array); // create count variable
$sequence = '020'; // print the number of numbers
function filter_phone_numbers($mobile_array, $sequence){
return array_filter($mobile_array, function ($item) use ($sequence) {
if (stripos($item, $sequence) !== false) {
return true;
}
return false;
});
}
$filtered_items = array_unique (filter_phone_numbers($mobile_array, $sequence)); //use array_unique in case we find same number that both contains or starts with sequence
echo count($filtered_items);
Or with preg_grep():
$mobile_list = '02000, 02032435, 039002300, 00305600';
$mobile_array = explode(",",$mobile_list); // turn into an array
$landlines = array_count_values($mobile_array); // create count variable
$sequence = preg_quote('020', '~'); ; // print the number of numbers
function grep_phone_numbers($mobile_array, $sequence){
return preg_grep('~' . $sequence . '~', $mobile_array);
}
//use array_unique in case we find same number that both contains or starts with sequence
$filtered_items = array_unique(grep_phone_numbers($mobile_array, $sequence));
echo count($filtered_items);
I recommend doing this with the database. The database is design to manage data and can do it a lot more efficient than PHP can. You can simply put it into a query and just get the result you want in 1 go:
SELECT * FROM phone_numbers WHERE number LIKE '020%'
If you get the data from the database anyways, that LIKE adds a little time to the query, but less that it takes PHP to loop, strpos and store the results. Also, as you return a smaller dataset, less resources are being used.
I am working in php and I am trying to create 1000 tickets in a database. Each ticket needs it's own unique code that consists of letters and numbers about 6 characters long.
EXP.
Tbl_Tickets
ID code
1 3F2jk7
2 2HGUF1
3 9FJDNJ
4 MFJEY9
5 23988D
I was wondering is there a simple way of doing this with php, or excel, or any other way for that matter. I know that i can use a random number generator, but the check for the Unique would have a large BigO notation and the check would get messy.
Unique is not compatible with random, but the following might suit:
=CHOOSE(RANDBETWEEN(1,2),RANDBETWEEN(0,9),CHAR(RANDBETWEEN(65,90)))
copied across to populate six columns (say A to F) with, in G:
=A1&B1&C1&D1&E1&F1
and both copied down to say row 1100. Then select G, copy Paste Special Values, and Remove Duplicates on ColumnG and select first 1000 entries.
You could easily create an array of strings in php and write it to a database:
function generateRandomString($length = 6, $letters = '1234567890QWERTYUIOPASDFGHJKLZXCVBNM'){
$s = '';
$lettersLength = strlen($letters)-1;
for($i = 0 ; $i < $length ; $i++){
$s .= $letters[rand(0,$lettersLength)];
}
return $s;
}
// Create an array with random strings
for ($i=0; $i<1000; $i++){
$ticket_numbers = array();
$ticket_number = generateRandomString();
while (in_array($ticket_number,$ticket_numbers))
$ticket_number = generateRandomString();
$ticket_numbers[] = $ticket_number;
}
// Write the array to a database
$con = mysqli_connect("myhost","myuser","mypassw","mybd") or die("Error");
foreach ($ticket_numbers as $number){
mysqli_query($con,"Your insert query using the value $number");
}
mysqli_close($con);
This should help you in the right direction though there are probably better ways to do this.
The function generateRandomString() was taken from How to generate random numbers/letters with PHP/Javascript
And another option. Encryption is guaranteed to be unique, so encrypting the numbers 0, 1, 2, ... will give you guaranteed unique random-seeming output. Six characters is 30 bits using Base32, or 36 bits using Base64. You will need a 30 (or 36 bit) cypher. Unless you have a library that includes Hasty Pudding cypher (unlikely) then just implement a simple four round Feistel cypher with the appropriate block size. It will not be completely secure, but it will be enough to defeat casual attacks.
This will produce random strings in column B with no repeats from B1 thru B1001
Sub Lottery()
Dim i As Long, j As Long, c As Collection
Set c = New Collection
v = Split("0,1,2,3,4,5,6,7,8,9,A,B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T,U,V,W,X,Y,Z", ",")
For i = 1 To 5000
can = ""
For j = 1 To 6
can = can & v(Application.RandBetween(0, 35))
Next j
On Error Resume Next
c.Add can, CStr(can)
On Error GoTo 0
If c.Count = 1000 Then Exit For
Next i
For i = 1 To 1000
Cells(i + 1, 2).Value = c(i)
Next i
End Sub
I am working on a Web Application that includes long listings of names. The client originally wanted to have the names split up into divs by letter so it is easy to jump to a particular name on the list.
Now, looking at the list, the client pointed out several letters that have only one or two names associated with them. He now wants to know if we can combine several consecutive letters if there are only a few names in each.
(Note that letters with no names are not displayed at all.)
What I do right now is have the database server return a sorted list, then keep a variable containing the current character. I run through the list of names, incrementing the character and printing the opening and closing div and ul tags as I get to each letter. I know how to adapt this code to combine some letters, however, the one thing I'm not sure about how to handle is whether a particular combination of letters is the best-possible one. In other words, say that I have:
A - 12 names
B - 2 names
C - 1 name
D - 1 name
E - 1 name
F - 23 names
I know how to end up with a group A-C and then have D by itself. What I'm looking for is an efficient way to realize that A should be by itself and then B-D should be together.
I am not really sure where to start looking at this.
If it makes any difference, this code will be used in a Kohana Framework module.
UPDATE 2012-04-04:
Here is a clarification of what I need:
Say the minimum number of items I want in a group is 30. Now say that letter A has 25 items, letters B, C, and D, have 10 items each, and letter E has 32 items. I want to leave A alone because it will be better to combine B+C+D. The simple way to combine them is A+B, C+D+E - which is not what I want.
In other words, I need the best fit that comes closest to the minimum per group.
If a letter contains more than 10 names, or whatever reasonable limit you set, do not combine it with the next one. However, if you start combining letters, you might have it run until 15 or so names are collected if you want, as long as no individual letter has more than 10. That's not a universal solution, but it's how I'd solve it.
I came up with this function using PHP.
It groups letters that combined have over $ammount names in it.
function split_by_initials($names,$ammount,$tollerance = 0) {
$total = count($names);
foreach($names as $name) {
$filtered[$name[0]][] = $name;
}
$count = 0;
$key = '';
$temp = array();
foreach ($filtered as $initial => $split) {
$count += count($split);
$temp = array_merge($split,$temp);
$key .= $initial.'-';
if ($count >= $ammount || $count >= $ammount - $tollerance) {
$result[$key] = $temp;
$count = 0;
$key = '';
$temp = array();
}
}
return $result;
}
the 3rd parameter is used for when you want to limit the group to a single letter that doesn't have the ammount specified but is close enough.
Something like
i want to split in groups of 30
but a has 25
to so, if you set a tollerance of 5, A will be left alone and the other letters will be grouped.
I forgot to mention but it returns a multi dimensional array with the letters it contains as key then the names it contains.
Something like
Array
(
[A-B-C-] => Array
(
[0] => Bandice Bergen
[1] => Arey Lowell
[2] => Carmen Miranda
)
)
It is not exactly what you needed but i think it's close enough.
Using the jsfiddle that mrsherman put, I came up with something that could work: http://jsfiddle.net/F2Ahh/
Obviously that is to be used as a pseudocode, some techniques to make it more efficient could be applied. But that gets the job done.
Javascrip Version: enhanced version with sort and symbols grouping
function group_by_initials(names,ammount,tollerance) {
tolerance=tollerance||0;
total = names.length;
var filtered={}
var result={};
$.each(names,function(key,value){
val=value.trim();
var pattern = /[a-zA-Z0-9&_\.-]/
if(val[0].match(pattern)) {
intial=val[0];
}
else
{
intial='sym';
}
if(!(intial in filtered))
filtered[intial]=[];
filtered[intial].push(val);
})
var count = 0;
var key = '';
var temp = [];
$.each(Object.keys(filtered).sort(),function(ky,value){
count += filtered[value].length;
temp = temp.concat(filtered[value])
key += value+'-';
if (count >= ammount || count >= ammount - tollerance) {
key = key.substring(0, key.length - 1);
result[key] = temp;
count = 0;
key = '';
temp = [];
}
})
return result;
}
General Overview:
The function below spits out a random ID. I'm using this to provide a confirmation alias to identify a record. However, I've had to check for collision(however unlikely), because we are only using a five digit length. With the allowed characters listed below, it comes out to about 33 million plus combinations. Eventually we will get to five million or so records so collision becomes an issue.
The Problem:
Checking for dupe aliases is inefficient and resource heavy. Five million records is a lot to search through. Especially when this search is being conducted concurrently by different users.
My Question:
Is there a way to 'auto increment' the combinations allowed by this function? Meaning I only have to search for the last record's alias and move on to the next combination?
Acknowledged Limitations:
I realize the code would be vastly different than the function below. I also realize that mysql has an auto increment feature for numerical IDs, but the project is requiring a five digit alias with the allowed characters of '23456789ABCDEFGHJKLMNPQRSTUVWXYZ'. My hands are tied on that issue.
My Current Function:
public function random_id_gen($length)
{
$characters = '23456789ABCDEFGHJKLMNPQRSTUVWXYZ';
$max = strlen($characters) - 1;
$string = '';
for ($i = 0; $i < $length; $i++) {
$string .= $characters[mt_rand(0, $max)];
}
return $string;
}
Why not just create a unique index on the alias column?
CREATE UNIQUE INDEX uniq_alias ON MyTable(alias);
at which point you can try your insert/update and if it returns an error, generate a new alias and try again.
What you really need to do is convert from base 10 to base strlen($characters).
PHP comes with a built in base_convert function, but it doesn't do exactly what you want as it will use the numbers zero, one and the letter 'o', which you don't have in your version. So you'll need a function to map the values from base_convert from/to your values:
function map_basing($number, $from_characters, $to_characters) {
if ( strlen($from_characters) != strlen($to_characters)) {
// ERROR!
}
$mapped = '';
foreach( $ch in $number ) {
$pos = strpos($from_characters, $ch);
if ( $pos !== false ) {
$mapped .= $to_characters[$pos];
} else {
// ERROR!
}
}
return $mapped;
}
Now that you have that:
public function next_id($last_id)
{
$my_characters = '23456789ABCDEFGHJKLMNPQRSTUVWXYZ';
$std_characters ='0123456789abcdefghijklmnopqrstuv';
// Map from your basing to the standard basing.
$mapped = map_basing($last_id, $my_characters, $std_characters);
// Convert to base 10 integer and increment.
$intval = base_convert($mapped, strlen($my_characters), 10);
$intval++;
// Convert to standard basing, then to our custom basing.
$newval_std = base_convert($intval, 10, strlen($my_characters));
$newval = map_basing($newval_std, $std_characters, $my_characters);
return $newval;
}
Might be some syntax errors in there, but you should get the gist of it.
You could roll your own auto-increment. It would probably be fairly inefficient though as you'd have to figure out where in the process your increment was. For instance, if you assigned the position in your random string as an integer and started with (0)(0)(0)(0)(0) that would equate to 22222 as the ID. Then to get the next one, just increment the last value to (0)(0)(0)(0)(1) which would translate into 22223. If the last one gets to your string length, then make it 0 and increment the second to last, etc... It's not exactly random, but it would be incremented and unique.
I have a PHP loop that adds data into a table cell. However, I want to apply a static size to the table cell, so if more data is returned than can fit inside the cell I want the excess characters to be cut off and end with a "..."
For example, one data entry has 270 characters, but only the first 100 are displayed in the table cell. Follow by a "..."
Any ideas on how to do this?
Thanks!
if (strlen($str) > 100) $str = substr($str, 0, 100) . "...";
You can use mb_strimwidth
printf('<td>%s</td>', mb_strimwidth($cellContent, 0, 100, '…'));
If you want to truncate with respect to word boundaries, see
Truncate a multibyte String to n chars
You can also control content display with the CSS property text-overflow: ellipsis
http://www.quirksmode.org/css/textoverflow.html
Unfortunately, browser support varies.
function print_dots($message, $length = 100) {
if(strlen($message) >= $length + 3) {
$message = substr($message, 0, $length) . '...';
}
echo $message;
}
print_dots($long_text);
$table_cell_data = ""; // This would hold the data in the cell
$cell_limit = 100; // This would be the limit of characters you wanted
// Check if table cell data is greater than the limit
if(strlen($table_cell_data) > $cell_limit) {
// this is to keep the character limit to 100 instead of 103. OPTIONAL
$sub_string = $cell_limit - 3;
// Take the sub string and append the ...
$table_cell_data = substr($table_cell_data,0,$sub_string)."...";
}
// Testing output
echo $table_cell_data."<br />\n";