<Results>
<id>673</id>
<dfdfsdfsdfs>2</dfdfsdfsdfs>
<sadasdsadsadsad>1067</sadasdsadsadsad>
</Results>
把<Results></Results>
里面的<xxxxxx>YYYYYYY</xxxxxx>全部
YYYYYY转换成123
<id>673</id>
<dfdfsdfsdfs>2</dfdfsdfsdfs>
<sadasdsadsadsad>1067</sadasdsadsadsad>
</Results>
把<Results></Results>
里面的<xxxxxx>YYYYYYY</xxxxxx>全部
YYYYYY转换成123
<Results>
<id>673</id>
<dfdfsdfsdfs>2</dfdfsdfsdfs>
<sadasdsadsadsad>1067</sadasdsadsadsad>
</Results>
html;
echo preg_replace('/>\d+</s','>123<',$s);