Let's say I have multidimensional array
var arr = [{
"id": "1",
"firstname": "SUSAN",
"dezibel": "91"
}, {
"id": "2",
"firstname": "JOHNNY",
"dezibel": "74"
}, {
"id": "3",
"firstname": "ANDREA",
"dezibel": "67"
}];
How can I sort it by "dezibel" but not ascending or descending, but closest to a giving number? For example,
var num = 78;
so target value is 78. and final sorting must be: 74, 67, 91.
You'll need to use a custom sort function that compares the absolute difference of each object's dezibel attribute from 78.
var arr = [{
"id": "1",
"firstname": "SUSAN",
"dezibel": "91"
}, {
"id": "2",
"firstname": "JOHNNY",
"dezibel": "74"
}, {
"id": "3",
"firstname": "ANDREA",
"dezibel": "67"
}];
num = 78;
arr.sort(
function(first,second){
var a = Math.abs(num - (+first.dezibel));
var b = Math.abs(num - (+second.dezibel));
return a - b;
});
alert(JSON.stringify(arr));Write a sort function which calculates the distance to your number:
arr.sort(function(a, b){
return Math.abs(num-a) - Math.abs(num-b);
});
Use this to sort the dezibel properties in your array. It will calculate the distance between each of them and num. It will then select the smaller of the two distances, and continue in this manner to sort the whole array.
Just sort by the absolute difference.
var arr = [{ "id": "1", "firstname": "SUSAN", "dezibel": "91" }, { "id": "2", "firstname": "JOHNNY", "dezibel": "74" }, { "id": "3", "firstname": "ANDREA", "dezibel": "67" }],
num = 78;
arr.sort(function (a, b) {
return Math.abs(a.dezibel - num) - Math.abs(b.dezibel - num);
});
document.write('<pre>' + JSON.stringify(arr, 0, 4) + '</pre>');.sort optionally takes a function. The function takes 2 values at a time, and compares them:
0.So, if you wanted to sort by dezibel in ascending order, you could do
arr.sort(function(a,b){
return a.dezibel- b.dezibel;
});
However, you want to sort by dezibel's distance from some number. To find the magnitude of the difference from 78 and the dezibel value, take the absolute value of the difference:
Math.abs(78 - a.dezibel)
Now, if we want to sort based on that value for each object, we can take the difference of that Math.abs call for both a and b:
arr.sort(function(a,b){
return Math.abs(78 - a.dezibel) - Math.abs(78 - b.dezibel);
});
You can use the array sort function for this:
arr.sort(function(a, b) {
return num - 1 * a.dezibel + num - 1 * b.dezibel
})
I would just add a distance and then sort it ...
num=78
for e in arr
e.dist=Math.abs(e.dezibel - num)
arr.sort (l,r) =>
if l.dist > r.dist then 1 else -1
delete the dist after
but put in one line is ok, too
arr.sort (l,r) =>
if Math.abs(l.dezibel - num) > Math.abs(r.dezibel - num) then 1 else -1
