1、顺序搜索

    1. function search(nums, value){
    2.   let index=-1;
    3.   for(let i=0; i<nums.length;i++){
    4.     if(nums[i]===value){
    5.       index=i;
    6.       breakk
    7.     }
    8.   }
    10.   return index;
    11. }

    2、二分搜索

    1. //nums是经过排序的
    2. function search(nums, value) {
    3.     let left = 0;
    4.     let right = nums.length - 1;
    6.     while (left <= right) {
    7.         let index = Math.floor((left + right) / 2);
    9.         if (nums[index] > value) {
    10.             right = index - 1;
    11.         }
    12.         else if (nums[index] < value) {
    13.             left = index + 1;
    14.         }
    15.         else {
    16.             return index;
    17.         }
    18.     }
    20.     return -1;
    21. }