试试这个简单的代码，它会像魔法一样工作!

let letters = "abcabcabcabcabc";
// we defined our variable or the name whatever
let a = -3;
let finalArray = [];
for (let i = 0; i <= letters.length; i += 3) {
    finalArray.push(letters.slice(a, i));
  a += 3;
}
// we did the shift method cause the first element in the array will be just a string "" so we removed it
finalArray.shift();
// here the final result
console.log(finalArray);

str.match(/.{3}/g); // => ['abc', 'def', 'ghi', 'jkl']

我的解决方案(ES6语法):

const source = "8d7f66a9273fc766cd66d1d";
const target = [];
for (
    const array = Array.from(source);
    array.length;
    target.push(array.splice(0,2).join(''), 2));

我们甚至可以这样创建一个函数:

function splitStringBySegmentLength(source, segmentLength) {
    if (!segmentLength || segmentLength < 1) throw Error('Segment length must be defined and greater than/equal to 1');
    const target = [];
    for (
        const array = Array.from(source);
        array.length;
        target.push(array.splice(0,segmentLength).join('')));
    return target;
}

然后你可以以一种可重用的方式轻松地调用函数:

const source = "8d7f66a9273fc766cd66d1d";
const target = splitStringBySegmentLength(source, 2);

干杯

如果你不想使用正则表达式…

var chunks = [];

for (var i = 0, charsLength = str.length; i < charsLength; i += 3) {
    chunks.push(str.substring(i, i + 3));
}

jsFiddle。

.．.否则正则表达式的解决方案是相当好的:)

const chunkStr = (str, n, acc) => {     
    if (str.length === 0) {
        return acc
    } else {
        acc.push(str.substring(0, n));
        return chunkStr(str.substring(n), n, acc);
    }
}
const str = 'abcdefghijkl';
const splittedString = chunkStr(str, 3, []);

干净的解决方案没有REGEX

function str_split(string, length = 1) {
    if (0 >= length)
        length = 1;
    
    if (length == 1)
        return string.split('');

    var string_size = string.length;
    var result = [];

    for (let i = 0; i < string_size / length; i++)
        result[i] = string.substr(i * length, length);

    return result;
}

str_split(str, 3)

基准测试:http://jsben.ch/HkjlU(不同浏览器的结果不同)

结果(Chrome 104)