废弃原因：属于非标准遗留特性，参数规则和substring、slice不一致，极易混淆，已被纳入ECMA附录B，仅为兼容旧代码保留，不推荐新代码使用。 废弃原因：语义不统一，标准规范已推出语义更清晰的替代方法，部分新版浏览器已逐步移除支持。 废弃原因：编码 ...

Docs rot faster than fruit. You refactor a function signature on Monday. The docs still show the old signature on Friday. By next month, half your documentation is lying to your users. Formatting is ...