Random

JavaScript Randomization examples

---

Random number in a range

Generate a random number in a range. Source

• Example:

  function getRandumNumber(min, max) {
      return Math.floor(Math.random() * (max - min + 1) + min);
  }

---

Random number with fixed length

Generate a random number with fixed length. Source

• Example:

  function getRandumNumber(length) {
      const min = Math.pow(10, (length-1));
      const max = Math.pow(10, (length));
      return Math.floor(Math.random() * (max - min) + min);
  }

---

Random string

Generate a random string. Source

• Example:

  function getRandomString(length) {
    const allowedCharacters = 'abcdefghijklmnopqrstuvwxyz0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ';
    const allowedCharacterLength = allowedCharacters.length;
  
    let result = '';
  
    for ( let i = 0; i < length; i++ ) {
      result += allowedCharacters.charAt(Math.floor(Math.random() *  allowedCharacterLength));
    }
  
    return result;
  }

---

Random UUID

Generate a random UUID. Source

• Example:

  function getUUID() {
    return ([1e7]+-1e3+-4e3+-8e3+-1e11).replace(/[018]/g, c =>
        (c ^ crypto.getRandomValues(new Uint8Array(1))[0] & 15 >> c / 4).toString(16)
    );
  }

---

Random color

Generate a random color. Source

• Example:

    function getRandomColor() {
        const availableCharacters = '0123456789ABCDEF';
        const availableCharacterLength = availableCharacters.length;
  
        let color = '#';
    
        for (let i = 0; i < 6; i++) {
          color += availableCharacters[Math.floor(Math.random() * availableCharacterLength)];
        }
    
        return color;
    }

---

Random date

Generate a random date. Source

• Example:

    function getRandomDate() {
        const maxDate = Date.now();
        const timestamp = Math.floor(Math.random() * maxDate);
        return new Date(timestamp);
    }

---

Random date in a range

Generate a random date in a range. Source

• Example:

    function getRandomDate(startDate, endDate) {
        const minValue = startDate.getTime();
        const maxValue = endDate.getTime();
        const timestamp = Math.floor(Math.random() * (maxValue - minValue + 1) + minValue);
        return new Date(timestamp);
    }

---