var arr = [];
arr.push(row1);
arr.push(row2);
...
arr.push(rown);
How to sort by row['key']?
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4 Answers
A JavaScript array has a built-in sort() method. In this case, something like the following would work:
arr.sort( function(row1, row2) {
var k1 = row1["key"], k2 = row2["key"];
return (k1 > k2) ? 1 : ( (k2 > k1) ? -1 : 0 );
} );
Comments
You call the sort function of an array with your comparator. A JavaScript comparator is just a function that returns -1, 0, or 1 depending on whether a is less than b, a is equal to b, or a is greater than b:
myarray.sort(function(a,b){
if(a < b){
return -1;
} else if(a == b){
return 0;
} else { // a > b
return 1;
}
});
This is just an example, your function can base the comparison on whatever you want, but it needs to return -1,0,1.
Hope this helps.
Comments
Here is set of functions if you want to sort asending, descending, or sort on multiple columns in an array.
var cmp = function(x, y){ return x > y? 1 : x < y ? -1 : 0; },
arr = [{a:0,b:0},{a:2,b:1},{a:1,b:2},{a:2, b:2}];
// sort on column a ascending
arr.sort(function(x, y){
return cmp( cmp(x.a, y.a), cmp(y.a, x.a) );
});
// sort on column a descending
arr.sort(function(x, y){
return cmp( -cmp(x.a, y.a), -cmp(y.a, x.a) );
});
// sort on columns a ascending and b descending
arr.sort(function(x, y){
return cmp([cmp(x.a, y.a), -cmp(x.b, y.b)], [cmp(y.a, x.a), -cmp(y.b,x.b)]);
});
To get an ascending sort, use "cmp(...)", and to get a descending sort, use "-cmp(...)"
And to sort on multiple columns, compare two arrays of cmp(...)
Comments
Consider the following code:
var arr = new Array();
for(var i = 0; i < 10; ++i) {
var nestedArray = [ "test", Math.random() ];
arr.push(nestedArray);
}
function sortBySecondField(a, b) {
var aRandom = a[1];
var bRandom = b[1];
return ((aRandom < bRandom) ? -1 : ((aRandom > bRandom) ? 1 : 0));
}
arr.sort(sortBySecondField);
alert(arr);
Now just change a sortBySecondField function to compare a['key'] instead of a[1] and do the same for b.
