如何根据特征过滤JSON数组并输出正确选项的索引

Got it, let's break down how to solve this. You've got a parsed array of option objects, and you need to find the index of the one where correct: true — here are the most straightforward ways to do it.

Method 1: Use Array.findIndex() (Most Concise) #

This built-in array method is made exactly for this scenario: it returns the index of the first element that matches your condition.

// Your parsed array from JSON
const options = [
  { correct: false },
  { correct: true },
  { correct: false },
  { correct: false }
];

// Find the index of the correct answer
const correctAnswerIndex = options.findIndex(option => option.correct === true);

// Output the result
console.log(`The correct answer is: ${correctAnswerIndex}`);

Notes:

• If no element with correct: true exists, findIndex() returns -1. You can add a quick check for this edge case:

  if (correctAnswerIndex !== -1) {
    console.log(`The correct answer is: ${correctAnswerIndex}`);
  } else {
    console.log("No correct answer found in the array.");
  }
  

Method 2: Manual Loop with forEach() #

If you prefer a more explicit approach, you can iterate through the array and track the index manually:

let correctAnswerIndex = -1;
const options = [
  { correct: false },
  { correct: true },
  { correct: false },
  { correct: false }
];

options.forEach((option, index) => {
  if (option.correct === true) {
    correctAnswerIndex = index;
  }
});

// Output the result
if (correctAnswerIndex !== -1) {
  console.log(`The correct answer is: ${correctAnswerIndex}`);
}

This works just fine, but findIndex() is more idiomatic and concise for this specific task.

内容的提问来源于stack exchange，提问作者TBG