使用JavaScript从纯文本过滤并生成指定JSON数组

Here's a practical, step-by-step solution to parse your plain text input into the exact JSON structure you need:

Step 1: Break Down the Input Structure #

Your input has two lines of trade data. Each line starts with an index, followed by a variable-length name segment, a shortform identifier, then a series of numeric values. We need to pull three key fields:

• traded: The unique shortform (like shortform1 or shortform2)
• close: The 4th numeric value immediately after the shortform
• previousClose: As specified in your target output, we'll use 355 (adjust this logic later if you need to pull it from a specific position in the input)

Step 2: JavaScript Code Implementation #

const inputText = `1 agri dev ban lt shortform1 346 346 343 343 9,671 346 3,330,659 78 -3.00 -0.87 3.00 0.87 361.80 400.07 449.86 472.00 283.00
2 Api Pwr Cpy shortform2 355 355 347 348 2,702 355 942,793 36 -7.00 -1.97 8.00 2.31 366.09 465.42 479.63 683.00 246.00`;

// Split input into individual lines, ignoring any empty lines
const lines = inputText.split('\n').filter(line => line.trim() !== '');

// Process each line to extract the required fields
const parsedData = lines.map(line => {
    // Split the line into parts, handling multiple spaces between elements
    const parts = line.split(/\s+/);
    
    // Find the shortform: it's the last non-numeric part before the first numeric value (after the initial index)
    let shortformIndex = -1;
    for (let i = 1; i < parts.length; i++) {
        if (!isNaN(parseFloat(parts[i])) && parts[i].trim() !== '') {
            shortformIndex = i - 1;
            break;
        }
    }
    const traded = parts[shortformIndex];
    
    // Extract the close value: 4th numeric entry after the shortform (strip commas from formatted numbers first)
    const closeValue = parseFloat(parts[shortformIndex + 4].replace(/,/g, ''));
    
    // Set previousClose (matches your target output; adjust if this needs to come from the input)
    const previousClose = 355;

    return {
        traded,
        close: closeValue,
        previousClose
    };
});

// Convert the parsed data to a formatted JSON string
const resultJSON = JSON.stringify(parsedData, null, 2);
console.log(resultJSON);

Step 3: Expected Output #

Running this code will log the following JSON array to your console:

[
  {
    "traded": "shortform1",
    "close": 343,
    "previousClose": 355
  },
  {
    "traded": "shortform2",
    "close": 348,
    "previousClose": 355
  }
]

Quick Adjustments #

• If previousClose should be pulled from a specific position in your input (instead of being hardcoded), replace const previousClose = 355; with something like const previousClose = parseFloat(parts[shortformIndex + 1].replace(/,/g, '')); (to use the first numeric value after the shortform).
• The code automatically handles numeric values with commas (like 9,671) by stripping commas before parsing to a number.
• The shortform detection works even if the name segment has a variable number of words (4 words in the first line, 3 in the second).

内容的提问来源于stack exchange，提问作者samcro