const values = [0.1 + 0.2, NaN, Infinity, -0, 42.6789];

const results = values.map((v, i) => {
  if (i === 0) return Number.isInteger(v) + " | " + v.toFixed(2);
  if (i === 1) return Number.isFinite(v) + " | " + Number.isNaN(v);
  if (i === 2) return Number.isFinite(v) + " | " + Number.MAX_SAFE_INTEGER;
  if (i === 3) return Object.is(v, -0) + " | " + (v === 0);
  if (i === 4) return v.toFixed(2) + " | " + v.toPrecision(4);
});

results.forEach(r => console.log(r));