这个字符怎么转成数组

Question

这个字符串怎么转成数组
let str = "[北京市, 海淀区]" ======> ["北京市","海淀区"]

Answer 1

如果没有涉及到嵌套的话，用正则就行，如果涉及到多层嵌套就比较麻烦了，内部括号里的逗号和普通的逗号不太好区分，比如[A, [B, C]]内部以逗号分隔会分成'A'、'[B'、'C]'。感觉得写个简单的解析器，规则很容易总结:
S -> [I, ...]
I -> s | S

class StrArrParser {
    constructor(str) {
        this.str = str;
        this.result= []
        this.index = 0;
        this.parse()
    }
    parse() {
        if(!this.str[this.index]) return;
        this.index = this.getNonBlankIndex();
        if(this.index<0) {
            throw new Error('格式错误')
        }
        if(this.str[this.index] === '[') {
            this.parseArr()
        } else {
            this.parseStr()
        }
    }
    getResult() {
        return this.result[0]||[];
    }
    getNextIndex(rule) {
        const checkRule = typeof rule === 'string'
            ? (s) => s === rule
            : (s) => rule.test(s)
        let index = this.index
        while(this.str[index]) {
            if(checkRule(this.str[index])) return index
            index++
        }
        return -1
    }
    getNonBlankIndex() {
        return this.getNextIndex(/\S/)
    }
    getArrStrContent() {
        if(this.str[this.index] !== '[') {
            throw new Error('判断错误')
        }
        const stack = ['[']
        let index = this.index + 1
        while(this.str[index] && stack.length) {
            if(this.str[index] === '[') {
                stack.push('[')
            }
            if(this.str[index] === ']') {
                stack.pop()
            }
            index++
        }
        if(stack.length) throw new Error('格式错误')
        return {
            str: this.str.substring(this.index+1, index),
            end: index - 1
        }
    }
    parseArr() {
        const {str, end} = this.getArrStrContent();
        const parser = new StrArrParser(str);
        this.result.push(parser.result)
        this.index = end + 1;
        this.parse()
    }
    parseStr() {
        const start = this.index;
        const end = this.getNextIndex(/,|\]/)
        const rst = this.str.substring(start, end).trim();
        rst && this.result.push(rst);
        this.index = end + 1
        this.parse()
    }
}

Answer 2

const result = '[北京市, 海淀区]'.slice(1, -1).split(',')
console.log(result)

Answer 3

看看我截图吧，被转义了

Answer 4

"[北京市, 海淀区]".replace(/^\[(.*?)\]$/, '$1').split(",");