从字符串php中删除一些字符

I have strings like this.

$50 From here i need only 50
$60.59 From here i need only 60, Need to remove $ and .59
€360 From here i need only 360.
€36.99 From here i need only 36 need to remove € and .99.
£900 From here i need only 900.
£90.99 From here i need only 90.

In Other word i need to remove all currency tag from the start of the string and i need only first amount. Hope my question is clear. Thanks

I would recommend not using a regular expression, as it's overkill for this scenario.

$str = (int)ltrim($str, '$£€');

this is all you need.

Performance vs Regex

I ran the above test through a script to see what the time difference is between my answer and using a RegEx, and on average the RegEx solution was ~20% slower.

<?php
function funcA($a) {
    echo (int)ltrim($a, '$£€');
};
function funcB($a) {
    echo preg_replace('/^.*?([0-9]+).*$/', '$1', $a);
};
//setup (only run once):
function changeDataA() {}
function changeDataB() {}

$loops = 50000;
$timeA = 0.0;
$timeB = 0.0;
$prefix =  str_split('€$€');

ob_start();
for($i=0; $i<$loops; ++$i) {
    $a = $prefix[rand(0,2)] . rand(1,999) . '.' . rand(10,99);

    $start = microtime(1);
    funcA($a);
    $timeA += microtime(1) - $start;

    $start = microtime(1);
    funcB($a);
    $timeB += microtime(1) - $start;
}
ob_end_clean();

$timeA = round(1000000 * ($timeA / $loops), 3);
$timeB = round(1000000 * ($timeB / $loops), 3);

echo "
TimeA averaged $timeA microseconds
TimeB averaged $timeB microseconds
";

Timings vary depending on system load, so times should be considered only relative to each other, not compared between executions. Also this isn't a perfect script for performance benchmarking, there are outside influences that can affect these results, but this gives a general idea.

TimeA averaged 5.976 microseconds
TimeB averaged 6.831 microseconds

This RegEx should do it

(\$|€|£)\d+

This is even better (thanks to Jan)

[$€£]\d+

Use it with PHP's Preg Match

preg_match — Perform a regular expression match

You could go for:

<?php

$string = <<<DATA
$50 From here i need only 50
$60.59 From here i need only 60, Need to remove $ and .59
€360 From here i need only 360.
€36.99 From here i need only 36 need to remove € and .99.
£900 From here i need only 900.
£90.99 From here i need only 90.
DATA;

# look for one of $,€,£ followed by digits
$regex = '~[$€£]\K\d+~';

preg_match_all($regex, $string, $amounts);
print_r($amounts);
/*
Array
(
    [0] => Array
        (
            [0] => 50
            [1] => 60
            [2] => 360
            [3] => 36
            [4] => 900
            [5] => 90
        )

)
*/

?>

See a demo on ideone.com.

Use regular expression. Ex:

$toStr = preg_replace('/^.*?([0-9]+).*$/', '$1', $fromStr);

See preg_replace documentation.

use below way

    $str = '$50 From here i need only 50
    $60.59 From here i need only 60, Need to remove $ and .59
    €360 From here i need only 360.
    €36.99 From here i need only 36 need to remove € and .99.
    £900 From here i need only 900.
    £90.99 From here i need only 90.';

    $arr_ = array('$','€','£');

    echo str_replace($arr_,'',$str);

$newString=$string;
$currencyArray = array("$","€","£"); //just add the new item if you want that to add more
foreach($currencyArray  as $value) 
  $newString= str_replace($value,"",$newString);   

$newString has what you need.