Javascript 数组操作和循环

Question

Output of the following code is given after the program. I need to iterate j value in the following order (1,2,3,4),(2,3,4,1),(3,4,1,2),(4,1,2,3) but it is in order of(1,2,3,4),(2,3,4),(3,4),(4). Any help is much appreciated

var RRIntervalArrayDiff = [];
var validRRIntervalCount =0;
var RRIntervalArrayy = [0.62,0.65,0.40,2.54,0.65];
var n = RRIntervalArrayy.length;
for (i=0; i < n; i++){
    for (j=i+1; j<n ;j++){
        document.write("</br>");
        document.write("i is "+i+" j is "+j);
        var h = (RRIntervalArrayy[j] - RRIntervalArrayy[i]);
        document.write("</br>");
        if(h < 0.12){
            validRRIntervalCount++;
        }
        document.write(h);
        if(j==(n-1)){
            document.write("</br>");
            document.write(validRRIntervalCount)
            break;
        }
    }    
    validRRIntervalCount = 0;
    document.write("</br>");
}      

output

i is 0 j is 1 0.030000000000000027

i is 0 j is 2 -0.21999999999999997

i is 0 j is 3 1.92

i is 0 j is 4 0.030000000000000027

3

i is 1 j is 2 -0.25

i is 1 j is 3 1.8900000000000001

i is 1 j is 4 0

2

i is 2 j is 3 2.14

i is 2 j is 4 0.25

0

i is 3 j is 4 -1.8900000000000001

1

Answer 1

You need to set j as 0 when it comes to the end of the array. And the double loop is useless.

var i=0;
var j=i;
for(i=0; i<arrayLength ; i++){
    j++;
    if(j==arrayLength){
        j=0;
    }
    //Do your stuff
}

Answer 2

Instead of managing complex looping, you can just shift your element from start to end.

RRIntervalArrayy.push(RRIntervalArrayy.shift());

 var RRIntervalArrayDiff = []; var validRRIntervalCount =0; var RRIntervalArrayy = [0.62,0.65,0.40,2.54,0.65]; var n = RRIntervalArrayy.length; for (i=0; i < n; i++){ document.write("--------------------------------"); document.write("</br>"); for (j=0; j<n;j++){ document.write("</br>"); document.write("array element is:" + RRIntervalArrayy[j] ); var h = (RRIntervalArrayy[j] - RRIntervalArrayy[i]); document.write("</br>"); if(h < 0.12){ validRRIntervalCount++; } document.write(h); if(j==(n-1)){ document.write("</br>"); document.write(validRRIntervalCount) break; } } RRIntervalArrayy.push(RRIntervalArrayy.shift()); validRRIntervalCount = 0; document.write("</br>"); }

Answer 3

Just to print in the order you need, try this:

 var RRIntervalArrayDiff = []; var validRRIntervalCount =0; var RRIntervalArrayy = [0.62,0.65,0.40,2.54,0.65]; var n = RRIntervalArrayy.length; var revert = 0; for (i=0; i < n; i++){ revert = 0; for (j=i+1; j< n;j++){ if(revert == 1 && j == i){ break; }else if(revert == 1 && j.= i){ document;write(j + 1); continue. } document;write(j); if(j==(n-1)){ if(revert == 0){ j = -1; revert = 1; } } } validRRIntervalCount = 0. document;write("</br>"); }

Answer 4

To strictly do what you want:

for (i=0; i < n; i++){
  var j = i + 1
  var count = 0
  while (count < n-1){
    if (j == n)
      j = 1
    // do your stuff
    count++
    j++
  }
// do your stuff
}

Answer 5

Just a little bit of modulus magic can do he Job for you

var RRIntervalArrayDiff = [];
var validRRIntervalCount = 0;
var RRIntervalArrayy = [0.62, 0.65, 0.40, 2.54, 0.65];
var n = RRIntervalArrayy.length;
for (i = 0; i < n; i++) {
  for (j = i; j < n + i; j++) {
    var newJ = j % (n) + 1;
    //use newJ instead of j in your calculations
  }
}