const searchRec = (arr,target,l,r) => { if(l > r) return -1; const m = Math.floor((l+r)/2); if(target === arr[m]) return m; else if(target >= arr[m]) return searchRec(arr,target,m+1,r); else return searchRec(arr,target,l,l,m-1); } const search = (arr,target) => searchRec(arr,target,0,arr.length-1); console.log(search([3,6,7,8,11,19,90],90));