JavaScript 指数运算符

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1) Current Task & Steps

Current task: Step 1 - 先写最常见：平方和立方
实现 powerPair(n)，返回 [平方, 立方]。

Write your code in `script.js` for the current Step.
Click "Run Validation" to check if rules pass.
Once current Step passes, the next step unlocks automatically.
You need to pass Step 1 first to unlock Step 2.

Step Deliverables (Check these)

Define function: powerPair(n)
Self-check: powerPair(3) => [9,27]

2) Beginner Explanation (Current Step)

Step task: 实现 powerPair(n)，返回 [平方, 立方]。
Define function(s): powerPair, then verify results with test inputs.
This step has a specific expected result. Focus on making the function return the correct value.
A function is a reusable block of code. Define it first, then call it.
`return` sends a result back. Without return, you usually can't get the function's result.

3) Starter Template (Type along)

function powerPair(n) {
  return null;
}
// Self-check: powerPair(3) should return [9,27]
console.log(powerPair(3));

4) Rule Validation & Hints

📋 当前任务 - Step 1

定义 powerPair
powerPair(3) = [9,27]

🔐 学习提示

📖 快速参考

不要把 ^ 当成次方，JavaScript 里 ^ 是按位异或，不是幂运算。

About This Exercise

很多同学第一次看到“几次方”会先想到 Math.pow()，其实 ES7 后你可以更直观地写：

base ** exp

这一关不会考你数学推导，只训练一件事：把题目里的“平方、立方、次方”准确写成代码。

Beginner⏱ 12-18 min

Learning Objectives

能写出平方、立方和任意次方
理解 **= 是“先计算幂再赋值”
养成把中间结果存变量再返回的好习惯

Scenario

你在实现一个“学习成长值”小功能：系统会基于初始值做平方放大，再用于评分展示。你需要把这几种幂运算写成可复用函数。

Why Do This

Frontend JS is not just about knowing the syntax — the key is reliably manipulating the DOM and managing interaction state.
Break down the event flow (trigger -> handle -> update UI) before coding, and you will make significantly fewer errors.
Rule-based validation helps you develop a testable frontend mindset.

Hands-on Practice

Write out the event flow in comments first, then implement the functions.
Add an edge case branch for invalid input or empty data.
Explain why each validation rule is needed.

Common Mistakes

Only testing the happy path without verifying edge inputs or repeated clicks.
Mixing event binding and state updates together, making future maintenance difficult.
Console output looks correct but the UI is not actually updated.

Deliverable

A reusable interaction component scaffold (event flow description + key functions + edge case handling).

My Progress

Completed Steps0 / 3

Total Attempts0

Best Score0%

Completion Criteria (Checkable)

Confirm before completing this Lab

All rules for the current step passCan explain each line of your codeCan name a real-world business scenario for this

Reflection Questions (Recommended)

Describe the event flow of this Lab in 2-3 sentences (trigger -> handle -> update).

What edge case did you add? Why is it easy to miss?

How confident are you with this interaction pattern now?

Not confident yet, need more practiceCan complete similar tasks independentlyCan teach others how to do it