Hatayı bulmama yardım edermisiniz?

Dil: Node.js 12.22.6, Express 4.17.2

Kod:
let lh = req.query.lh + ''
lh = lh.split(',')
lh[0] = lh[0].split('')
lh[1] = lh[1].split('')
lh[0] = (lh[0]).slice(0,lh[0].length - 1)
lh[1] = (lh[1]).slice(0,lh[1].length - 1)
lh[0] = lh[0].join('')
lh[1] = lh[1].join('')
lh[0] = lh[0] >>> 0
lh[1] = lh[1] >>> 0

Hata: TypeError: lh[0].slice is not a function