类型操作符$type 操作符$type根据类型查询。可取值和JavaScript类型取值相同。number 数值string 字符串,注意s小写object 对象取出所有age里面是数值类型的文档对象db.c1.find({age:{$type:"number"}});可以借助$exis...
package com.sky.testmodule.controller;import com.alibaba.fastjson.JSON;import com.sky.testmodule.constant.TestConstant;import com
Given two integers representing the numerator and denominator of a fraction, return the fraction in string format.
Given a non-empty string s and a dictionary wordDict containing a list of non-empty words, determine if s can be segmented into a space-separated sequence of on...
Implement a basic calculator to evaluate a simple expression string.