JS judge whether the year is a leap year and the number of days in the month

Leap years can be 4 Divisible and not divisible by 100 to be divisible by , Or can be 400 to be divisible by .

Demand from echarts Histogram jump and query the value of current month

Simple code

function year（）{
    
　　if(year%4 == 0 && year%100 != 0 || year%400 == 0){
    
         console.log(' Leap year ');
　　}else{
    
　   console.log(' Ordinary year ');
　　}
}

Local code

  created() {
    
    let shippingCompanyId = this.$route.params.shippingCompanyId
    let month = this.$route.params.month
    // console.log(' route 1',this.$cloneDeep(this.$route.params))
    if(month && month != undefined){
    
      let strYear= this.$route.params.month.substring(0,4)
      let submonth = month.substr(month.lastIndexOf("-") + 1,4);  // After intercepting the last dot 4 Characters 
      this.tempSearch.startTime = month + '-01 00:00:00'
      // **************************
      if(['01','03','05','07','08','10','12'].includes(submonth)){
    
        this.tempSearch.endTime = month + '-31 23:59:59'
      }else if(['02'].includes(submonth)){
    
        if(strYear%4==0 && strYear%100!=0 || strYear%400==0){
     //  Leap year   Leap years can be 4 Divisible and not divisible by 100 to be divisible by , Or can be 400 to be divisible by .
          this.tempSearch.endTime = month + '-29 23:59:59'
        }else{
     //  Ordinary year 
          this.tempSearch.endTime = month + '-28 23:59:59'
        }
      }else{
    
        this.tempSearch.endTime = month + '-30 23:59:59'
      }
      // **************************
    }
    if(shippingCompanyId){
    
      this.args.search.shippingCompanyId = shippingCompanyId
      this.getList() //  To obtain a list of 
    }else{
    
      this.getList() //  To obtain a list of 
    }
  },