Question 393177 in Javascript Question posted in
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Javascript – new Date() validation of string with number

When inputing string with number the new Date() is missbehaving, is there another way how to achieve this without regex?

let string = 'some string 1';
let invalid = new Date(string);

it is still parsing as a Date value

Mon Jan 01 2001 00:00:00 GMT+0000 (Greenwich Mean Time)

I’m expecting it as an invalid date

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2

Answers


  1. Chosen as BEST ANSWER
    0

    Update

    let string = 'some string 1';
let invalid = new Date(string.replace(/s/g, ''));

    Seem to resolve to Invalid Date as i want to and it seem to proper validate all dates also human readable dates like Sun, 1 Dec 2024


  2. 0 
        function validateDate(dateString) {
  // Attempt to parse the date string
  const timestamp = Date.parse(dateString);
  
  // Check if the parsed timestamp is NaN (invalid date)
  if (isNaN(timestamp)) {
    return 'Invalid string';
  }
  
  // Convert the timestamp back to a date string
  const date = new Date(timestamp);
  const dateISO = date.toISOString().slice(0, 10); // Extract the YYYY-MM-DD part
  const timeISO = date.toISOString(); // Full ISO format
  
  // Compare the original string with the formatted date strings
  if (dateString === dateISO || dateString === timeISO) {
    return 'Valid date';
  }
  
  return 'Invalid string';
}

let string = 'some string 1';
let invalid = validateDate(string);

    Now the function will return the date is valid or not.

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