JSFiddle - React, Tailwind, and code Playground
JavaScript
var a = [
{"column":2, "row":21},
{"column":2, "row":22.0},
{"column":2, "row":24},
{"column":2, "row":25.0},
{"column":6, "row":23}
];
var lastId;
var b = [];
for (var i = 0; i < a.length; i++) {
if (lastId == a[i]['column']) {
[b[b.length-1]['row']].push(a[i]['row']);
} else {
b[b.length] = (a[i]); //длина нового массива
lastId = a[i]['column'];
}
}
console.log(b);