Map array of arrays to list

Question

I have an array of answers, sorted by the question they belong to, like this:

sortedAnswers= [[Answer1, Answer2, Answer3, Answer4],[AnswerA, AnswerB, AnswerC, AnswerD]...]

I'm trying to render a list of ListItemButton in React. I have tried before

    <ButtonGroup
      fullWidth
      orientation='vertical'
      onClick={handleSubmit}
      onChange={handleChange}
    >
      {sortedAnswers.map((item) =>
        <ListItemButton>{item}</ListItemButton> )}
    </ButtonGroup>

But it doesn't work as expected, I get this:

I want each answer to have a ListItemButton, so 4 buttons per question. How can I get the answer for the first array in the button?

Answer 1

Use nested loops to iterate over all answers depending on how you want your layout to look:

const sortedAnswers = [
  [Answer1, Answer2, Answer3, Answer4],
  [AnswerA, AnswerB, AnswerC, AnswerD]
];

{sortedAnswers.map(answers => (
  <ButtonGroup
    fullWidth
    orientation="vertical"
    onClick={handleSubmit}
    onChange={handleChange}
  >
    {answers.map(answer => (
      <ListItemButton>{answer}</ListItemButton>
    ))}
  </ButtonGroup>
))}

Answer 2

As you mentioned Error: Cannot read property of undefined (read 'map') , please add conditional check before mapping.

{sortedAnswers.length > 0 && (
  <ButtonGroup fullWidth orientation='vertical' onClick={handleSubmit} onChange={handleChange}>
    {sortedAnswers[0].map((answer, index) => (
      <ListItemButton key={index}>{answer}</ListItemButton>
    ))}
  </ButtonGroup>
)}