【前端技巧】括号合法性校验

@Author：Outman
@Date：2023-02-01

括号合法性校验

/**
 * 括号合法性校验
 * @desc 判定括号嵌套顺序、括号配对数量是否符合规范
 * @param {String} str
 * @return {boolean}
 * @example [{（()）}] -> true   {[（(）}] -> false
 */
const IS_LEAGL_BRACKETS = (str) => {
  const len = str.length;
  if (!len) return true;

  const stack = [];

  // 若需判定其他括号，可在下方补充定义"括号常量"
  const L_BRACKET = "([{（";
  const R_BRACKET = ")]}）";
  const MATCH_MAP = {
    ")": "(",
    "]": "[",
    "}": "{",
    "）": "（",
  };

  // 遍历字符，进行括号嵌套合法性校验
  for (let i = 0; i < len; i++) {
    const char = str[i];
    if (L_BRACKET.includes(char)) {
      stack.push(char);
    } else if (R_BRACKET.includes(char)) {
      const top = stack[stack.length - 1];
      if (MATCH_MAP[char] === top) {
        stack.pop();
      } else {
        return false;
      }
    }
  }
  // 检查栈是否为空，进行配对数量校验
  return !stack.length;
};


export {
  IS_LEAGL_BRACKETS
};