1Math.round(0.9); // 1
2Math.round(5.5); // 6
3Math.round(-5.95); // -6
4
5Math.round(-5.5); // -5 (note)

1(2.34).toFixed(1); // '2.3'
2(2.35).toFixed(1); // '2.4'
3
4(2.55).toFixed(1); // '2.5' (note)

1(2.005).toFixed(2); // '2.00'
2(2.0050000000000001).toFixed(2); // '2.00'
3(2.0051).toFixed(2); // '2.01'
4(2.005000000000001).toFixed(2); // '2.01'

 1// float to binary conversion
 2function floatToBinary(floatNum) {
 3  const buffer = new ArrayBuffer(8);
 4  const floatView = new Float64Array(buffer);
 5  const intView = new Uint8Array(buffer);
 6
 7  floatView[0] = floatNum;
 8
 9  let binary = "";
10  for (let i = intView.length - 1; i >= 0; i--) {
11    let byte = intView[i];
12    for (let j = 7; j >= 0; j--) {
13      binary += (byte >>> j) & 1;
14    }
15  }
16  return binary;
17}
18
19floatToBinary(2.005); //              '0 10000000000 0000000010100011110101110000101000111101011100001010'
20floatToBinary(2.0050000000000001); // '0 10000000000 0000000010100011110101110000101000111101011100001010'
21floatToBinary(2.0051); //             '0 10000000000 0000000010100111000111011110011010011010110101000011'
22floatToBinary(2.005000000000001); //  '0 10000000000 0000000010100011110101110000101000111101011100001100'

1// Comparing floating-point numbers
22.005 === 2.0050000000000001; // true

 1// binary to float64 conversion
 2
 3function binaryToFloat64(binaryString) {
 4  if (binaryString.length !== 64) {
 5    throw new Error("Binary string must be 64 characters long.");
 6  }
 7
 8  const sign = parseInt(binaryString[0], 2);
 9  const exponent = parseInt(binaryString.substring(1, 12), 2) - 1023;
10  const mantissa = parseInt(binaryString.substring(12), 2) / Math.pow(2, 52);
11
12  return Math.pow(-1, sign) * (1 + mantissa) * Math.pow(2, exponent);
13}
14
15binaryToFloat64(
16  "0100000000000000000010100011110101110000101000111101011100001010"
17); // 2.005