How to insert a string inside another string? - php

Just looked at function
str_pad($input, $pad_length, $pad_str, [STR_PAD_RIGHT, STR_PAD_LEFT, or STR_PAD_BOTH])
which helps to pad some string on left, right or on both sides of a given input.
Is there any php function which I can use to insert a string inside an input string?
for example ..
$input = "abcdef";
$pad_str = "#";
so if I give insert index 3, it inserts "#" after first 3 left most characters and $input becomes "abc#def".
thanks

You're looking for a string insert, not a padding.
Padding makes a string a set length, if it's not already at that length, so if you were to give a pad length 3 to "abcdef", well it's already at 3, so nothing should happen.
Try:
$newstring = substr_replace($orig_string, $insert_string, $position, 0);
PHP manual on substr_replace

you need:
substr($input, 0, 3).$pad_str.substr($input, 3)

Bah, I misread the question. You want a single insert, not insert every X characters. Sorry.
I'll leave it here so it's not wasted.
You can use regular expressions and some calculation to get your desired result (you probably could make it with pure regexp, but that would be more complex and less readable)
vinko#mithril:~$ more re.php
<?php
$test1 = "123123123";
$test2 = "12312";
echo puteveryXcharacters($a,"#",3);
echo "\n";
echo puteveryXcharacters($b,"#",3);
echo "\n";
echo puteveryXcharacters($b,"$",3);
echo "\n";
function puteveryXcharacters($str,$wha,$cnt) {
$strip = false;
if (strlen($str) % $cnt == 0) {
$strip = true;
}
$tmp = preg_replace('/(.{'.$cnt.'})/',"$1$wha", $str);
if ($strip) {
$tmp = substr($tmp,0,-1);
}
return $tmp;
}
?>
vinko#mithril:~$ php re.php
123#123#123
123#12
123$12

Related

Php check exist have how many random int numbers in string

I have rand function like;
$mynumbers = rand(1111,9999);
echo $mynumbers;
Example output is
3582
and I have another strings
$mystring = "Ja9Js78I4PhXiF464R6s7ov8IUF"; (Have 1 number, must be turn 1 (only 8 have))
$mystring2 = "Ja3Js73I4P1X5iF564R8s2ov8IUF"; (Have 4 numbers, must be turn 4 (have all of them))
And i want to know this with function ;
$mystring is have, how many numbers ? inside $mynumbers and how many time ? passed when this process ? How can i do it ?
per your last comment. Treat the integer as a string (PHP is good at that). And iterate by character.
<?php
$foo = '1234';
$mystring = [];
$mystring[] = 'A1B2KLDLDF3'; //3
$mystring[] = 'XXXX4XXXX'; //1
foreach ($mystring as $key => $string) {
echo "mystring {$key}: ";
$c = 0;
foreach(str_split($foo) as $char) {
$c = $c + substr_count($string, $char);
}
echo $c . '<br/>';
}
mystring 0: 3
mystring 1: 1
As this is PHP you also need to be aware of mb_ multibyte functions. See: http://php.net/manual/en/function.mb-substr-count.php
Update:
Sounds like you should clean up the string you are checking then if you want to discard all duplicates... Could then of course use a substr or other method perhaps more performant than substr_count.
$mystring = 'A111111B2KLDLDF333'; //3
$mystring = implode('',array_unique(str_split($mystring)));
//gives 'A1B2KLDF3'

How to convert Exponentials to Decimals in PHP

I have a string like this:
9.018E-14
Now I want to convert to this to the normal decimal numbers.
MyGeekPal has a nice article on it.
Code:
<?php
$total_time = 2.8848648071289E-5;
echo exp2dec($total_time);
function exp2dec($number) {
preg_match('/(.*)E-(.*)/', str_replace(".", "", $number), $matches);
$num = "0.";
while ($matches[2] > 0) {
$num .= "0";
$matches[2]--;
}
return $num . $matches[1];
}
?>
If your input is a float
If you have $number = 0.00023459 then printing this value in PHP will probably result in this exponential format. It doesn't mean the variable is stored that way; it's just an output artefact.
Use printf to work around this and gain control over your numeric output.
If your input is a string
Why the complexity?
$matches = Array();
if (preg_match('/(.*)E-(.*)/', $number, $matches)) {
$number = $matches[1] * pow(10, -1*$matches[2]);
}
Though you can tighten up the regex a bit:
$matches = Array();
if (preg_match('/(\d+(?:\.\d+)?)E(-?\d+)/i', $number, $matches)) {
$number = (float)$matches[1] * pow(10, (int)$matches[2]);
}
Live demo
EDIT: Here is some PHP magic:
$stringval = "12e-3";
$numericval = 0 + $stringval;
From the PHP docs:
If the string does not contain any of the characters '.', 'e', or 'E' and the numeric value fits into integer type limits (as defined by PHP_INT_MAX), the string will be evaluated as an integer. In all other cases it will be evaluated as a float.
If you need a more flexible format (e.g. extract four numbers from the same string), use sscanf like this:
$stringval = "12e-3";
$numericval = sscanf($stringval, "%f")[0];
echo $numericval;

Keep generating random number until one does not exist - PHP

I have a string with a lot of different numbers. I am trying to create a new random number and add it to the string.
The part I need help with is "if the number already exists in the string, create a new random number, and keep doing it until a number is created that does not yet exist in the string".
// $string contains all the numbers separated by a comma
$random = rand(5, 15);
$existing = strpos($string, $random);
if ($existing !== false) { $random = rand(5, 15); }
$new_string = $string.",".$random;
I know this isn't quite right as it will only check if it's existing once. I need it to keep checking to make sure the random number does not exist in the string. Do I use a while loop? How would I change this to work properly?
Your help is much appreciated.
A solution that works like Endijs ... but I want to post that :)
$string = '6,7,8';
$arr = explode(',', $string);
$loop = true;
while($loop) {
$randomize = rand(5, 15);
#var_dump($randomize);
$loop = in_array($randomize, $arr);
if (!$loop) {
$arr[] = $randomize;
}
}
$newString = implode(',', $arr);
var_dump($newString);
Checking data in string is not the best solution. Thats because if your random number will be '5', and in string you will have 15, strpos will find accurance of 5. I would convert string to array and do search on it.
$a = explode(',' $your_string);
$random = rand(5, 15);
while (in_array($random, $a))
{
$random = rand(5, 15);
}
$a[] = $random;
$your_string = implode(',', $a);
Update - just be careful - if all possible variables will be already in string, it will be endless loop.

How to find first non-repetitive character from a string?

I've spent half day trying to figure out this and finally I got working solution.
However, I feel like this can be done in simpler way.
I think this code is not really readable.
Problem: Find first non-repetitive character from a string.
$string = "abbcabz"
In this case, the function should output "c".
The reason I use concatenation instead of $input[index_to_remove] = ''
in order to remove character from a given string
is because if I do that, it actually just leave empty cell so that my
return value $input[0] does not not return the character I want to return.
For instance,
$str = "abc";
$str[0] = '';
echo $str;
This will output "bc"
But actually if I test,
var_dump($str);
it will give me:
string(3) "bc"
Here is my intention:
Given: input
while first char exists in substring of input {
get index_to_remove
input = chars left of index_to_remove . chars right of index_to_remove
if dupe of first char is not found from substring
remove first char from input
}
return first char of input
Code:
function find_first_non_repetitive2($input) {
while(strpos(substr($input, 1), $input[0]) !== false) {
$index_to_remove = strpos(substr($input,1), $input[0]) + 1;
$input = substr($input, 0, $index_to_remove) . substr($input, $index_to_remove + 1);
if(strpos(substr($input, 1), $input[0]) == false) {
$input = substr($input, 1);
}
}
return $input[0];
}
<?php
// In an array mapped character to frequency,
// find the first character with frequency 1.
echo array_search(1, array_count_values(str_split('abbcabz')));
Python:
def first_non_repeating(s):
for i, c in enumerate(s):
if s.find(c, i+1) < 0:
return c
return None
Same in PHP:
function find_first_non_repetitive($s)
{
for($i = 0; i < strlen($s); $i++) {
if (strpos($s, $s[i], $i+1) === FALSE)
return $s[i];
}
}
Pseudocode:
Array N;
For each letter in string
if letter not exists in array N
Add letter to array and set its count to 1
else
go to its position in array and increment its count
End for
for each position in array N
if value at potition == 1
return the letter at position and exit for loop
else
//do nothing (for clarity)
end for
Basically, you find all distinct letters in the string, and for each letter, you associate it with a count of how many of that letter exist in the string. then you return the first one that has a count of 1
The complexity of this method is O(n^2) in the worst case if using arrays. You can use an associative array to increase it's performance.
1- use a sorting algotithm like mergesort (or quicksort has better performance with small inputs)
2- then control repetetive characters
non repetetive characters will be single
repetetvives will fallow each other
Performance : sort + compare
Performance : O(n log n) + O(n) = O(n log n)
For example
$string = "abbcabz"
$string = mergesort ($string)
// $string = "aabbbcz"
Then take first char form string then compare with next one if match repetetive
move to the next different character and compare
first non-matching character is non-repetetive
This can be done in much more readable code using some standard PHP functions:
// Count number of occurrences for every character
$counts = count_chars($string);
// Keep only unique ones (yes, we use this ugly pre-PHP-5.3 syntax here, but I can live with that)
$counts = array_filter($counts, create_function('$n', 'return $n == 1;'));
// Convert to a list, then to a string containing every unique character
$chars = array_map('chr', array_keys($counts));
$chars = implode($chars);
// Get a string starting from the any of the characters found
// This "strpbrk" is probably the most cryptic part of this code
$substring = strlen($chars) ? strpbrk($string, $chars) : '';
// Get the first character from the new string
$char = strlen($substring) ? $substring[0] : '';
// PROFIT!
echo $char;
$str="abbcade";
$checked= array(); // we will store all checked characters in this array, so we do not have to check them again
for($i=0; $i<strlen($str); $i++)
{
$c=0;
if(in_array($str[$i],$checked)) continue;
$checked[]=$str[$i];
for($j=$i+1;$j<=strlen($str);$j++)
{
if($str[$i]==$str[$j])
{
$c=1;
break;
}
}
if($c!=1)
{
echo "First non repetive char is:".$str[$i];
break;
}
}
This should replace your code...
$array = str_split($string);
$array = array_count_values($array);
$array = array_filter($array, create_function('$key,$val', 'return($val == 1);'));
$first_non_repeated_letter = key(array_shift($array));
Edit: spoke too soon. Took out 'array_unique', thought it actually dropped duplicate values. But character order should be preserved to be able to find the first character.
Here's a function in Scala that would do it:
def firstUnique(chars:List[Char]):Option[Char] = chars match {
case Nil => None
case head::tail => {
val filtered = tail filter (_!=head)
if (tail.length == filtered.length) Some(head) else firstUnique(filtered)
}
}
scala> firstUnique("abbcabz".toList)
res5: Option[Char] = Some(c)
And here's the equivalent in Haskell:
firstUnique :: [Char] -> Maybe Char
firstUnique [] = Nothing
firstUnique (head:tail) = let filtered = (filter (/= head) tail) in
if (tail == filtered) then (Just head) else (firstUnique filtered)
*Main> firstUnique "abbcabz"
Just 'c'
You can solve this more generally by abstracting over lists of things that can be compared for equality:
firstUnique :: Eq a => [a] -> Maybe a
Strings are just one such list.
Can be also done using array_key_exists during building an associative array from the string. Each character will be a key and will count the number as value.
$sample = "abbcabz";
$check = [];
for($i=0; $i<strlen($sample); $i++)
{
if(!array_key_exists($sample[$i], $check))
{
$check[$sample[$i]] = 1;
}
else
{
$check[$sample[$i]] += 1;
}
}
echo array_search(1, $check);

Remove last character from a variable and then multiply against another variable

I have a whole bunch of percentages stored as XX% (e.g. 12%, 50%, etc..) I need to remove the percentage sign and then multiply the percent against another variable thats just a number (e.g. 1000, 12000) and then output the result. Is there a simple way to strip the percentage sign and then calculate the output with PHP? Or should I consider some sort of JS solution?
You could use rtrim():
$value = ((int) rtrim('12%', '%')) * 1000';
Edit
You don't strictly need to call rtrim() , as it casts to an int ok with the percentage sign. It is probably cleaner to strip it though.
var_dump (12 === (int) '12%');
//output: bool(true)
You can make use of preg_replace_callback as:
$input = '12%, 50%';
$input = preg_replace_callback("|(\d+)%|","replace_precent",$input);
echo $input; // 12000, 50000
function replace_precent($matches) {
return $matches[1] * 1000;
}
Try this:
$number = str_replace('%', '', '100%');
$result = intval($number) * 5000; // or whatever number
echo $result;
If you use trim() or str_replace() in PHP you can remove the percent sign. Then, you should be able to multiply the resulting number (php is weakly typed after all).
<?php
$number = str_replace("%", "", $percentString);
$newNumber = ((int) $number) * 1000;
echo $newNumber;
?>
You can use str_replace. You can also pass an array of subjects into str_replace to have them all replaced.
<?php
$number = str_replace("%", "", $percentage);
$result = $number * $other_var;
print $result;
?>
<?php
$input=array('15%','50%','10.99%','21.5%');
$multiplier=1000;
foreach($input as $n){
$z=floatval($n)*$multiplier;
print("$z<br>");
}
?>

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