base64_encode是加密,而base64_decode是解密

base64_encode    语法:string base64_encode(string data);

$string='www.zhix.net智昕网络'; //定义字符串
echo base64_encode($string);  // 输出编码后的内容为 d3d3LnpoaXgubmV05pm65piV572R57uc

base64_decode    语法:string base64_decode(string data);

$string='d3d3LnpoaXgubmV05pm65piV572R57uc';     //定义字符串
echo base64_decode($string); //输出解码后的内容 www.zhix.net智昕网络