text: 
  exports.min = function min (array) {
      if (array === undefined || array.length === 0) return 0;
    let arr = array.flat().sort((a,b) => {return a-b});
    return arr[0];
  }
  
  exports.max = function max (array) {
      if (array === undefined || array.length === 0) return 0;
      let arr = array.flat().sort((a,b) => {return b - a});
      return arr[0];
  }
  
  exports.avg = function avg (array) {
      if (array === undefined || array.length === 0) return 0;
      return array.reduce((a,b) => {return a+b}) / array.length;
  }
  