### base64_encode() #### 說明 `string base64_encode ( string $data )` 使用 base64 對 data 進行編碼，數據要比原始數據多占用 33% 左右的空間。 設計此種編碼是為了使二進制數據，例如電子郵件的主體可以通過非純 8-bit 的傳輸層傳輸。 #### 示例 Example #1 ~~~ <?php $str = 'This is an encoded string'; echo base64_encode($str); ?> ~~~ 以上例程會輸出： VGhpcyBpcyBhbiBlbmNvZGVkIHN0cmluZw== * * * * * Example #2 A function I'm using to return local images as base64 encrypted code, i.e. embedding the image source into the html request. This will greatly reduce your page load time as the browser will only need to send one server request for the entire page, rather than multiple requests for the HTML and the images. Requests need to be uploaded and 99% of the world are limited on their upload speed to the server. ~~~ <?php function base64_encode_image ($filename=string,$filetype=string) { if ($filename) { $imgbinary = fread(fopen($filename, "r"), filesize($filename)); return 'data:image/' . $filetype . ';base64,' . base64_encode($imgbinary); } } ?> ~~~ used as so ~~~ <style type="text/css"> .logo { background: url("<?php echo base64_encode_image ('img/logo.png','png'); ?>") no-repeat right 5px; } </style> ~~~ or `<img src="<?php echo base64_encode_image ('img/logo.png','png'); ?>"/>`