为什么我的代码不正确地比较日期？

Question

我想检查一下日期是否在这个范围内。我创建了两个函数，第一个func转换类型str至今，第二个func必须找到结果。

let probeArray = [{price: 123, date: '2021-11-27'}, 
{price: 13, date: '2021-11-15'}, 
{price: 1, date: '2021-10-2'}, 
{price: 17, date: '2021-10-1'}];


let startDate = '2021-10-1';
let endDate = '2021-10-20';

// transform str to Date
const toDate = (dateStr) => {
    const [year,month,day] = dateStr.split("-");
    // console.log('check date')
    // console.log([day, month, year])
    return new Date(year, month - 1, +day+1);
  }


function get_staticstic(probeAr, start, end){
    
    let result = null;
    let maxDate = toDate(start);
    let minDate = toDate(end);

    for (let tempEvent of probeAr){
        let currentDate = toDate(tempEvent.date);
        console.log('maxDate', maxDate);
        console.log('minDate', minDate);
        console.log('currentDate',currentDate);

    
        if (currentDate >= minDate && currentDate <= maxDate ){
             console.log('Correct Date');
        }
        else{
            console.log('Out Side range!!');
        }
    

    }
    return result
}
get_staticstic(probeArray, startDate, endDate);

但在开始后，所有日期的结果都是‘外侧范围！’。

​

​

Answer 1

与代码有关

• 函数中的toDate错误。授权应该是return new Date(year, +month - 1, day);。不需要添加1和日期。另外，对于年份和日期来说，数字也不是必须的，它们也可以是字符串。get_staticstic.

中minDate和maxDate的

• 错误

工作部件

​

let probeArray = [
  { price: 123, date: '2021-11-27' },
  { price: 13, date: '2021-11-15' },
  { price: 1, date: '2021-10-2' },
  { price: 17, date: '2021-10-1' }
];


let startDate = '2021-10-1';
let endDate = '2021-10-20';

// transform str to Date
const toDate = (dateStr) => {
  const [year, month, day] = dateStr.split("-");
  // console.log('check date')
  // console.log([day, month, year])
  return new Date(year, +month - 1, day);
}

function get_staticstic(probeAr, start, end) {
  let result = null;
  let minDate = toDate(start);
  let maxDate = toDate(end);
  console.log('maxDate', maxDate);
  console.log('minDate', minDate);
  for (let tempEvent of probeAr) {
    let currentDate = toDate(tempEvent.date);
    console.log('currentDate', currentDate);
    if (currentDate >= minDate && currentDate <= maxDate) {
      console.log('Correct Date');
    }
    else {
      console.log('Out Side range!!');
    }
  }
  return result
}
get_staticstic(probeArray, startDate, endDate);

​

更好的方法

因为所有的日期字符串都是标准格式的，所以不需要为日期编写解析器函数。可以使用new Date(dateString)方法直接将日期对象转换为日期对象。

工作部件

​

let probeArray = [
  { price: 123, date: '2021-11-27' },
  { price: 13, date: '2021-11-15' },
  { price: 1, date: '2021-10-2' },
  { price: 17, date: '2021-10-1' }
];


let startDate = '2021-10-1';
let endDate = '2021-10-20';


function get_staticstic(probeAr, start, end) {
  let result = null;
  let minDate = new Date(start);
  let maxDate = new Date(end);
  console.log('maxDate', maxDate);
  console.log('minDate', minDate);
  for (let tempEvent of probeAr) {
    let currentDate = new Date(tempEvent.date);
    console.log('currentDate', currentDate);
    if (currentDate >= minDate && currentDate <= maxDate) {
      console.log('Correct Date');
    }
    else {
      console.log('Out Side range!!');
    }
  }
  return result
}
get_staticstic(probeArray, startDate, endDate);

​

Answer 2

您应该将minDate设置为开始日期，maxDate设置为结束日期。你做了相反的事。

​

let probeArray = [{price: 123, date: '2021-11-27'}, 
{price: 13, date: '2021-11-15'}, 
{price: 1, date: '2021-10-2'}, 
{price: 17, date: '2021-10-1'}];


let startDate = '2021-10-1';
let endDate = '2021-10-20';

// transform str to Date
const toDate = (dateStr) => {
    const [year,month,day] = dateStr.split("-");
    // console.log('check date')
    // console.log([day, month, year])
    return new Date(year, month - 1, +day+1);
  }


function get_statistic(probeAr, start, end){
    
    let result = null;
    let minDate = toDate(start);
    let maxDate = toDate(end);

    for (let tempEvent of probeAr){
        let currentDate = toDate(tempEvent.date);
        console.log('maxDate', maxDate);
        console.log('minDate', minDate);
        console.log('currentDate',currentDate);

    
        if (currentDate >= minDate && currentDate <= maxDate ){
             console.log('Correct Date');
        }
        else{
            console.log('Out Side range!!');
        }
    

    }
    return result
}
get_statistic(probeArray, startDate, endDate);

​