echo $keyword = "上海|北京!成都 深圳";
echo "<br />";
$old1 = array("/(\s*)(\s)(\s*)/","/(\s*)(\|)(\s*)/","/(\s*)(!)(\s*)/");
$new1 = array('" "','"|"','" "!');
echo $keyword3="\"".preg_replace($old1,$new1,$keyword)."\"";
//输出:"上海"|"北京" "!成都" "深圳"echo $keyword = "上海 | 北京 !成都 深圳";
echo "<br />";
$old1 = array("/(\s*)(\s)(\s*)/","/(\s*)(\|)(\s*)/","/(\s*)(!)(\s*)/");
$new1 = array('" "','"|"','" "!');
echo $keyword3="\"".preg_replace($old1,$new1,$keyword)."\"";
//输出:"上海" ""|"" "北京" "" "!成都" "深圳"上面两种情况:第一种是显示是对的,第二种给各符号间加了空格输去就错误了。请问多余的空格怎么屏蔽掉?正则表达式
echo $keyword = "上海|北京!成都 深圳";
echo "<br />";
$old1 = array("/(\s*)(\s)(\s*)/","/(\s*)(\|)(\s*)/","/(\s*)(!)(\s*)/");
$new1 = array('" "','"|"','" "!');
echo $keyword3="\"".preg_replace($old1,$new1,$keyword)."\"";
//输出:"上海"|"北京" "!成都" "深圳"echo $keyword = "上海 | 北京 !成都 深圳";
$keyword = str_replace(" ","",$keyword);
echo "<br />";
$old1 = array("/(\s*)(\s)(\s*)/","/(\s*)(\|)(\s*)/","/(\s*)(!)(\s*)/");
$new1 = array('" "','"|"','" "!');
echo $keyword3="\"".preg_replace($old1,$new1,$keyword)."\"";
//输出:"上海" ""|"" "北京" "" "!成都" "深圳"
$keyword = "上海 | 北京 !成都 深圳";//输出:"上海"|"北京" "!成都" "深圳"
echo "<br />";
$old1 = array("/!?[^\s!|]+/", "/\s+/", "/\s*\|\s*/", '/""/');
$new1 = array('"$0"', ' ', '|', '" "');
echo $keyword3 = preg_replace($old1,$new1,$keyword);
$old1 = array("/(\s*)(\|)(\s*)/","/(\s*)(!)(\s*)/","/(\s*)(\s)(\s*)(?!\")/");
$new1 = array('"|"','" "!','" "');
$keyword = str_replace(" ","",$keyword);
echo "<br />";
$old1 = array("/(\s*)(\|)(\s*)/","/(\s*)(!)(\s*)/","/(\s*?)(\s)(\s*?)/");
$new1 = array('"|"','" "!','" "');
echo $keyword3="\"".preg_replace($old1,$new1,$keyword)."\"";
//输出:"上海" ""|"" "北京" "" "!成都" "深圳"
试试