Question

我正在尝试获取字符串的长度并用星号（*）替换其第一个和后三个字符，并获取字符串长度而不使用函数中的任何PHP构建。

strlen - substr - preg_replace

示例：$string = "123456789"; $new_string = "***456***";

有可能吗？

我检查了许多教程，但无法弄明白。请帮忙。谢谢！

Answer 1

通用解决方案：

$string = "123456789";
$i = 0;
$limit = 3;
while (isset($string[$i])) {
    if ($i < $limit) {
        $string[$i] = '*';
    }
    $i++;
}
// you can rewrite this as loop
$string[$i - 1] = '*';
$string[$i - 2] = '*';
$string[$i - 3] = '*';

从php7.1开始，允许否定字符串索引：

$string = "123456789";
// you can rewrite it to a loop too
$string[0] = $string[1] = $string[2] = $string[-1] = $string[-2] = $string[-3] = '*';
echo $string;

没有任何功能的解决方案，但它会发出PHP Notice，您可以使用@来阻止它：

$string = "123456789";
$i = 0;
$limit = 3;
while (true) {
    if ($string[$i] == '') {
        break;
    }

    if ($i < $limit) {
        $string[$i] = '*';
    }
    $i++;
}
/* Simplified version:
while ($string[$i] != '') {
    if ($i < $limit) {
        $string[$i] = '*';
    }
    $i++;
}
*/
$string[$i - 1] = '*';
$string[$i - 2] = '*';
$string[$i - 3] = '*';

echo $string;

Answer 2

你可以通过循环来实现它。（没有内置函数）

$string = "123456789";
$i = 0;
$new_str = "";
while(true)
{
  $val = @$string[$i];
  if($val == "")
    break;
  if($i<3)
    $new_str .= "*";
  else
    $new_str .= $val;
  $i++;
}


for($j=0;$j<$i;$j++)
{
  if($j >= ($i-3))
    $new_str[$j]="*";
}
echo $new_str;

DEMO

Answer 3

我不知道你为什么不想使用任何PHP函数。但是，它仍然有可能。

TinyMCE

将回应此

   <?php

function privacy($string)
{

    //get the string length   

    $i = 0;

    /*  
    while (isset($string[$i])) {
    $i++;
    }
    */

    while ($string[$i] !== "") {
        $i++;
    }

    //replace the first and last 3 characters of the $string with a star
    //if the length is bigger than or equals to 6
    if ($i >= 6) {
        for ($x = 0; $x < 3; $x++) {
            $string[$x]      = "*";
            $string[$i - $x] = "*";
        }
    }
    return $i . "<br>" . $string;
}

echo privacy("123456789");

?>

我认为这是获取字符串长度并替换第一个和最后3个字符而不会产生混淆的最简单方法。到目前为止！

祝你好运！

Answer 4

您可以像访问数组一样访问字符串。

  function readURL(input) {
        var file = document.getElementById("article_file").value;
        console.log(file);
        var originalname = file.replace(/C:\\fakepath\\/i, '');
        console.log(name);
        if (DST()) {
            // Daylight Savings, EDT is UTC-4
            var offset = "-4";
        } else {
            // Not Daylight Savings, EST is UTC-5
            var offset = "-5";
        }
        var today = calcTime(offset);

        var month = today.getMonth() + 1;

        // appends 0 to monthes under 10
        if (month < 10)
            month = "0" + month.toString();

        if ($('table.appendo.image-uploader tbody tr').length > 2)
            $('table.appendo.image-uploader tbody tr').each(function (i, ele) {
                if(i==1)
                {
                     $('#image-preview-path').attr('src','src="/images/tp.gif"');
                     $('#image-path').attr('value','');
                }
                else if (i > 1)
                {
                    $(ele).remove();
                }
            });
        $('.upload-article').attr('name', 'Filedata[]');

        var files = $('#article_file')[0].files;
        var name = [];
        var extension = ['.jpg','jpeg','.gif','.png'];
        var flag = 1;
        name['invalid'] = 'invalid';
        for (var z = 0; z < files.length; z++){
            var ext = (files[z].name.substr(-4)).toLowerCase();
            if($.inArray(ext, extension) != -1){

            } else {
                flag = 2;
            }
        }
        var count = files.length;
        if(count <= '6') {
        if(flag == 1) {
        for (var x = 0; x < files.length; x++)
        {

            if (x == 0) {
                var file = files[x];
                var hello = file['name'].replace(/\s/g, '');
                var file_name = hello.replace(/[^.a-z0-9_-\s]/gi, '').replace(/[_\s]_/g, '-');
                name[file['size']] = file_name;
                console.log(files[x]);
                var reader = new FileReader();
                reader.addEventListener('load', function (e) {
                    console.log(e)

                    $('#image-preview-path').attr('src', e.target.result);
                    $('#image-path').attr('value', "/images/uploads/" + today.getFullYear() + "/" + month + "/" + today.getDate() + "/" + name[e.total]);

                });
                reader.onerror = function (event) {
                    console.error("File could not be read! Code " + event.target.error.code);
                };
                reader.readAsDataURL(file);
            } else {
                var file = files[x];
                var hello = file['name'].replace(/\s/g, '');
                var file_name = hello.replace(/[^.a-z0-9_-\s]/gi, '').replace(/[_\s]_/g, '-');
                name[file['size']] = file_name;
                console.log(files[x]);
                var reader = new FileReader();
                reader.addEventListener('load', function (e) {
                    console.log(e)
                    if ($('table.appendo>tbody:eq(0)>tr').length - 1 > 0)
                        index = $('table.appendo>tbody:eq(0)>tr').length - 1
                    else
                        index = 'invalid';
                    var table = $('table.appendo tbody tr:eq(1)').clone();
                    table.find('img').attr('id', 'image-preview-path');
                    table.find('img').attr('src', e.target.result);
                    table.find('input').attr('id', 'image-path');
                    table.find('input').attr('value', "/images/uploads/" + today.getFullYear() + "/" + month + "/" + today.getDate() + "/" + name[e.total]);
                    $('table.appendo.image-uploader tbody').append(table);

                });
                reader.onerror = function (event) {
                    console.error("File could not be read! Code " + event.target.error.code);

                };
                reader.readAsDataURL(file);
            }
        }
      } else {
          alert('Not a valid file extension.');
          $('#article_file').val("");
        } 
      } else {
          alert('You have attempted to queue too many files.\nYou may select six file.');
          $('#article_file').val("");
      }
    }

但我目前还不确定如何在不使用功能构建的情况下获得最后3个

php获取字符串长度并替换第一个和最后3个字符而不使用函数

4 个答案: