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使用PHP[复制]查找并替换字符串中子字符串的最后一个实例

php

-1

Mr. B · 技术社区 · 6 年前

我有一个动态的运动列表。每项运动以 , . 最后 , 使用删除 $sports = substr($sports, 0, -2); . 现在我想知道如何替换最后一个 , (逗号空格)带 , and (逗号和空格)。我可能错过了它,但我看不到这个函数。有没有一种或另一种创造性的方式来实现它?

原始列表

Football, Soccer, Basketball, Swimming, Baseball, Golf,

所需列表

Football, Soccer, Basketball, Swimming, Baseball, and Golf

5 回复 | 直到 6 年前

ezw 6 年前

$str = substr("Football, Soccer, Basketball, Swimming, Baseball, Golf, ", 0, -2);

$last_comma_position = strrpos($str, ',');

if($last_comma_position != false)
{
    echo substr_replace($str, ' and', $last_comma_position, 1);
}

http://php.net/substr_replace

或作为函数

function replace_last($haystack, $needle, $replaceWith)
{
    $last_position = strrpos($haystack, $needle);

    if($last_position != false)
    {
        return substr_replace($haystack, $replaceWith, $last_position, strlen($needle));
    }
}

$str = substr("Football, Soccer, Basketball, Swimming, Baseball, Golf, ", 0, -2);

echo replace_last($str, ',', ' and');

两种打印输出

Football, Soccer, Basketball, Swimming, Baseball and Golf

Anwar 6 年前

你可以利用 explode() / implode() 执行此操作。检查 live example here .

$list = 'Football, Soccer, Basketball, Swimming, Baseball, Golf, ';

function display( $string ) {
  // Splitting the list by comma
  $str = explode(',', $string);

  // Removing empty items
  $str = array_filter($str, function($item) {
    return strlen(trim($item)) > 0;
  });

  // prepeding "and" before the last item only if it contains more than one item
  $size = count($str);

  if( $size > 1 ) {
    $str[$size - 1] = "and " . (string) $str[$size - 1];
  }

  // Make list great (string) again
  $str = implode(', ', $str);  

  return $str;
}


echo display($list);

将回显:

足球、足球、篮球、游泳、棒球和高尔夫

bos570 6 年前

你可以试试你自己的方法。像这样的事情:

$string = "Football, Soccer, Basketball, Swimming, Baseball, Golf,"; 

function addAndToList($string) {

$string = substr($string, 0, -1);
$stringArray = explode(',', $string); 

$resultString = ''; 
foreach ($stringArray as $index => $val) {
  if (!isset($stringArray[$index+1])) 
       $resultString .= 'and '.$val; 
  else 
      $resultString .= $val.', ';
}

return $resultString; 
}

echo addAndToList($string);

Félix Adriyel Gagnon-Grenier 6 年前

如果变量已定义,请尝试此操作:

$arr = array_reverse(explode(', ', $sports));
$last = array_shift($arr);
$arr[0] .= " and {$last}";
$sports = implode(', ', array_reverse($arr));
echo "$sports\n";

helvete rosaforrestiana 6 年前

说明:

匹配字符串的最后一个字
由空格分隔
将其存储到反向引用伪变量中 $1
添加所需字符串

#!/usr/bin/env php
<?php

$sports = "Football, Soccer, Basketball, Swimming, Baseball, Golf, ";
$sports = substr($sports, 0, -2);

echo preg_replace('/ ([a-zA-Z]+)$/', ' and $1', $sports) . "\n";

此代码段输出:

Football, Soccer, Basketball, Swimming, Baseball, and Golf

该解决方案可以在以下方面进行验证 demo .