如何在JavaScript中以循环方式访问数组 [英] How to access array in circular manner in JavaScript

问题描述

我有一个像 [A，B，C，D] 这样的数组。我想在for循环中访问该数组，如

I have an array like [A,B,C,D]. I want to access that array within a for loop like as

var arr = [A,B,C,D];

var len = arr.len;
for(var i = 0;i<arr.len;i++){
    0 - A,B,C
    1 - B,C,D
    2 - C,D,A
    3 - D,A,B
}

我想要要在JavaScript中访问它，任何想法？

I want to access that like in JavaScript, any ideas?

推荐答案

试试这个：

var arr = ["A","B","C","D"];
for (var i=0, len=arr.length; i<len; i++) {
    alert(arr.slice(0, 3).join(","));
    arr.push(arr.shift());
}

如果不改变数组，它将是

Without mutating the array, it would be

for (var i=0, len=arr.length; i<len; i++) {
    var str = arr[i];
    for (var j=1; j<3; j++)
        str += ","+arr[(i+j)%len]; // you could push to an array as well
    alert(str);
}
// or
for (var i=0, len=arr.length; i<len; i++)
    alert(arr.slice(i, i+3).concat(arr.slice(0, Math.max(i+3-len, 0)).join(","));

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