JS生成随机数

const randomNum = (min = 0, max = 0, decimal) => {
    if (typeof decimal === 'undefined') {
        let minDecimal = String(min);
        minDecimal =
            minDecimal.indexOf('.') + 1
                ? minDecimal.length - (minDecimal.indexOf('.') + 1)
                : 0;
        let maxDecimal = String(max);
        maxDecimal =
            maxDecimal.indexOf('.') + 1
                ? maxDecimal.length - (maxDecimal.indexOf('.') + 1)
                : 0;
        decimal = minDecimal > maxDecimal ? minDecimal : maxDecimal;
    }
    return (Math.random() * (max - min) + min).toFixed(decimal);
};