Randomization

JavaScript Randomization examples

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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);
}

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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);
}

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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;
}

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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)
    );
}

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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;
}

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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);
}

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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);
}

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