Javascript toFixed function

Question

The expected result of:

(1.175).toFixed(2) = 1.18 and
(5.175).toFixed(2) = 5.18

But in JS showing:

Answer 1

obj = {
    round(val) {
      const delta = 0.00001
      let num = val
      if (num - Math.floor(num) === 0.5) {
        num += delta
      }
      return Math.round(num + delta)
    },
  fixed(val, count = 0) {
      const power = Math.pow(10, count)
      let res = this.round(val * power) / power
      let arr = `${res}`.split('.')
      let addZero = ''
      for (let i = 0; i < count; i++) {
        addZero += '0'
      }
      if (count > 0) {
        arr[1] = ((arr[1] || '') + addZero).substr(0, count)
      }
      return arr.join('.')
  }
}
obj.fixed(5.175, 2)

// "5.18"