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NorthLandsWeather.com
搜索引擎算法实验报告_搜索引擎算法优化测试与结果分析报告
graph TD A[“undefined variable in line 1”] --> B{错误类型判定} B -->|未声明引用| C[ReferenceError: xxx is not defined] B -->|已声明但未初始化| D[TypeError: Cannot read property 'x' of undefined] C --> E[检查 script 标签顺序/ESM import 时机] D --> F[添加可选链操作符 user?.name 或空值合并 user ?? {}]
