发生这种情况是因为您使用的是 includes 方法在字符串我n您的js文件受最新JavaScript版本 ECMAScript 6 支持，而android kitkat webview不支持此版本。

This is happening because you are using includes method on string in your js file, which is supported in latest JavaScript Version ECMAScript 6 and android kitkat webview doesn't support this version.

使用 indexOf 代替 includes

var str = "Hello world, welcome to the universe.";

var n = str.includes("world");
# Replace above line of code and use indexOf. 

var n = str.indexOf("world") > -1;