Assuming that you want the translations performed on the server side (PHP) you can use
file_get_contents to fetch data from Google Translate API. Then you need to parse the response and get translated text. You need to get
API KEY to access the Translate service.
Code:
<?php
$string = 'Hello World';
$source_lang = 'en';
$target_lang = 'zh-CN'
header ( "Content-Type: text/html;charset=utf-8" );
$data = file_get_contents ( 'https://www.googleapis.com/language/translate/v2?key=INSERT-YOUR-KEY&q='.urlencode($string).'&source='.$source_lang.'&target='.$target_lang );
$data = json_decode ( $data );
$translated = $data->data->translations->[0]->translatedText;
echo $translated;
?>