獲取文件後綴名的幾種方式

PHP

使用strrpos，分割字符串

<?php
function suffix($name){
    $index = strrpos($name,".");
    return substr($name,$index,strlen($name)-$index);
}
echo suffix('koastal.png');

使用pathinfo，獲取後綴名

<?php
function suffix($name){
    return pathinfo($name,PATHINFO_EXTENSION);
}
echo suffix('koastal.png');

Node.js

lastIndexOf類似php中的strrpos

function suffix(name){
    var index = name.lastIndexOf('.');
    return name.substring(index);
}
var suffix = suffix('koastal.png');
console.log(suffix);

path模塊

const path = require('path');
var suffix = path.extname('koastal.png');
console.log(suffix);