如何用JavaScript实现数组乘法生成重复数字字符串

Got it, let's sort out this problem for you! The key issue here is that you're treating the numbers as numeric values (hence getting multiplication results like 1*10=10) instead of converting them to strings to repeat their literal representation.

Here's a straightforward JavaScript function that does exactly what you need:

function repeatNumbers(arr) {
  // Process each subarray into a repeated string
  const resultSegments = arr.map(([number, repeatCount]) => {
    // Convert the number to a string, then repeat it repeatCount times
    return number.toString().repeat(repeatCount);
  });
  
  // Join all segments with ", " to match your expected output format
  return resultSegments.join(', ');
}

// Test the examples you provided
console.log(repeatNumbers([[1, 10]])); // Outputs: "1111111111"
console.log(repeatNumbers([[1, 2], [2, 3]])); // Outputs: "11, 222"

Let's break down how this works: #

• Destructuring in map: We use ([number, repeatCount]) to pull the two values out of each subarray directly, making the code cleaner and easier to read.
• String conversion: number.toString() turns the numeric value into its string equivalent (so 1 becomes "1"). This is crucial because the repeat() method only exists on strings—numbers don't have this method, which is why your earlier numeric approach didn't work.
• Repeat the string: repeat(repeatCount) takes the string and duplicates it exactly repeatCount times.
• Join segments: Finally, join(', ') combines all the repeated strings into one single string separated by , , matching the format you showed in your examples.

Bonus: Handling edge cases #

This function also works with multi-digit numbers! For example:

console.log(repeatNumbers([[123, 4]])); // Outputs: "123123123123"

Just make sure the second value in each subarray is a positive integer—if you pass 0 or a negative number, repeat() will return an empty string, which might not be what you want.

内容的提问来源于stack exchange，提问作者TorontoJ10