javascript - 二进制搜索 - javascript - 为什么数组中的最后一项导致超出最大调用堆栈？

Question

写这篇文章是为了尝试构建一个二进制搜索。它绝不是重构最多的代码，但想知道为什么除了 X 是数组中的最后一个值(即 x = 77)之外一切正常？

function binary_search(x, arr) {
    var len = arr.length - 1 //because index starts at 0
    var min = arr[0]
    var max = arr[0]    
    var new_arr = []

if(x < arr[0] || x > arr[len]) 
    //console.log(arr[len])
    console.log (x + " is not within array range.")
else 
    find_x(x, arr)


function find_x(x, arr) {
    var mid = Math.floor(arr.length/2) //takes care of odd numbered elements in array

    if (x === arr[mid]) 
        console.log("Found " + x)

    else if(x < arr[mid]) 
    {
        max = arr[mid]
        new_arr = arr.slice(0, mid)
        find_x(x, new_arr)
    }
    else if(x > arr[mid]) 
    {
        min = arr[mid]
        new_arr = arr.slice(mid, len)
        find_x(x, new_arr)
    }
    else
        console.log(x + " is not in array.")
}
}

var arr = [1,12,43,55,66,77]
binary_search(77, arr)

Answer 1

var len = arr.length

没有-1，否则你切断了最后一个元素

Zero-based index at which to end extraction. slice extracts up to but not including end.

发现了一个 google chrome 调试器 - 你应该有一天尝试一下

JSFiddle:http://jsfiddle.net/HC6yL/

引用资料:

• https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/slice