JSFiddle - React, Tailwind, and code Playground

JavaScript

var objArray = [
  {
    "something": {
      "terms": {
          "span": [
            9,
            12
          ],
          "value": "1g",
          "label": "grams"
        },
      "span": [
        9,
        12
      ],
      "weight": 0.29,
      "value": "1gm"
    }
  },
  {
    "something": {
      "terms": {
          "span": [
            16,
            20
          ],
          "value": "30ml",
          "label": "liters"
        },
      "span": [
        16,
        20
      ],
      "weight": 0.35,
      "value": "30ml"
    }
  }
];

    var byWeight = objArray.slice(0);
    var sorted = byWeight.sort(function(a,b) { return a.something.weight - b.something.weight; } );
    console.log(sorted[0].something.weight);