JavaScript instance code to find data using dichotomy

//Dialogue method to check data
 var arr=[41,43,45,53,44,95,23];

 var b=44;

 var min=0;

 var max=;

 for(var i=1;i<;i++){ //The outer loop controls the number of sorting times
  for(var j=0;j<-i;j++){//The inner loop controls the number of loops
    if(arr[j]<arr[j+1]){

    z=arr[j];

    arr[j]=arr[j+1];

    arr[j+1]=z;

    }

     }

     }

    // alert(arr[3])

  while(true){           //Two-part search means first sorting a set of data in order, dividing the set of data into two from the middle to see which range you want to find the number in, and then dividing it into two until you find
/* for(var i=0;i<;i++)*/  //Write this wrong? Until this number
   var zjs=parseInt((min+max)/2); //Because (min+max)/2 may be a decimal, add an integer to cast
   if(zjs==min){    When the array of numbers to be found is an array of even numbers, the number of numbers remaining is2When，Need to add a condition and make a judgment                 

     if(b=arr[zjs+1]){

       alert(zjs+1);

       break;

       }

       }

   if(b==arr[zjs]){

     alert(zjs)

     break;}

   else if(b>arr[zjs]){

    min=zjs; }

    else{max=zjs}} 

var arr = new Array(80,70,86,58,90,35,89,67,50,100);

  var sum = 0;

  var maxd = 0;

  var mind = 100;  //If you want to check the minimum number, it is best to use the maximum number of full scores as the base number that can be compared.
  for(var i=0;i<;i++){

    sum = sum +arr[i];

    if(arr[i]>maxd){

      maxd = arr[i];

    }

    if(arr[i]<mind){

      mind = arr[i];

    }

        }

  alert(sum);

  alert(maxd);

  alert(mind); 

//var a=7;

 var a=parseInt(prompt("Please enter a number"));

 var x=0;

 var arr=[1,2,3,4,5]

 for(var i=0;i<;i++){

   if(a==arr[i]){

     x=1;

     break;}}

    if(x==0){

      (a)}

      alert()