面试题库

5 天提示词工程零基础

D3 结构化输出：JSON schema、模板与变量、多语言输出

• 提示词模板里哪些内容该做成变量，哪些该写死？变量多了会有什么问题？In a prompt template, what should become a variable and what should stay constant, and what goes wrong when you have too many variables?

  国内高频海外高频进阶#prompt-template#structured-output

  分析过程 · 先想清楚再作答

  1. 这题看起来是设计题，实际在考「有没有维护过一份跑在生产里的提示词」。没维护过的人会把所有能变的都做成变量，觉得灵活；维护过的人知道每个变量都是一条测试维度。
  2. 拆法：判据只有一条——下一次调用还会一样的是常量，可能不一样的是变量。角色、任务、约束、schema 通常是常量；输入文本、输出语言、团队默认值是变量。
  3. 再答代价：每多一个变量，提示词的可能形态多一个维度，测试集要覆盖的组合翻倍；变量之间还可能互相影响（语言变量与格式说明冲突）。所以变量越少越好，只取过一个值的「变量」应该变回常量。
  4. 结论：模板是一个有名字、有参数签名的函数，变量是它的参数，常量是函数体；这样提示词才有身份，才能版本化、才能写测试。
  5. 追问：多语言应该是变量还是多份模板？变量——只有一份模板，语言只影响给人读的字段，枚举与标识符不跟着变；否则改一条规则要改多份，三个月后一定分叉。

  How to reason about it · think before answering

  1. It looks like a design question but really asks whether you have maintained a prompt in production. The untested instinct is to parameterize everything; experience teaches that every variable is a test dimension.
  2. One rule: what stays the same on the next call is a constant, what may differ is a variable. Role, task, constraints and schema are usually constants; input text, output language and team defaults are variables.
  3. Then the cost: each variable adds a dimension to the space of prompts, doubling the combinations a test set must cover, and variables can interact. Fewer is better; a variable that only ever took one value should become a constant.
  4. Conclusion: the template is a named function with a signature; variables are parameters, constants are the body. That identity is what makes versioning and testing possible.
  5. Follow-up: is multi-language a variable or separate templates? A variable — one template, language affects only human-facing fields, enums and identifiers never change; separate copies drift within months.

  答题要点

  • 判据：下一次调用还一样的是常量，可能不一样的是变量
  • 角色、任务、约束、schema 是常量；输入文本、输出语言、默认值是变量
  • 每个变量都是一条测试维度，变量越少越好，只取过一个值的变回常量
  • 多语言是一个变量，只影响给人读的字段，枚举与标识符不变

  Key points

  • Rule: same on the next call means constant, may differ means variable
  • Role, task, constraints and schema are constants; input text, output language and defaults are variables
  • Every variable is a test dimension, so keep them minimal and fold single-valued ones back into constants
  • Multi-language is one variable affecting only human-facing fields; enums and identifiers stay fixed