编辑代码

function binarySearch(arr: Array<number>, tar: number): number {
    let left = 0, right = arr.length-1
    while(left <= right) {
        let mid = Math.floor((left + right) / 2)
        if(arr[mid] === tar) return mid
        if(arr[mid] < tar) left = mid+1
        else right = mid-1
    }
    return -1
}

console.log(binarySearch([1,2,5,6,7,8,9,10], 8))