分享十个常用的 js函数

function isEmpty(value) {  
    return value === null || value === undefined || value === '';  
}

function getCookie(name) {  
    let cookieArr = document.cookie.split(";");  
    for(let i = 0; i < cookieArr.length; i++) {  
        let cookiePair = cookieArr[i].split("=");  
        if(name == cookiePair[0].trim()) {  
            return decodeURIComponent(cookiePair[1]);  
        }  
    }  
    return null;  
}

function getQueryParams(url) {  
  let urlObj = new URL(url);  
  let params = new URLSearchParams(urlObj.search);  
  return params;  
}

function getCurrentDateTime() {  
  let now = new Date();  
    
  let year = now.getFullYear();  
  let month = now.getMonth() + 1;  
  let day = now.getDate();  
  let hours = now.getHours();  
  let minutes = now.getMinutes();  
  let seconds = now.getSeconds();  
    
  // 格式化日期时间字符串  
  let formattedDateTime = `${year}-${padZero(month, 2)}-${padZero(day, 2)} ${padZero(hours, 2)}:${padZero(minutes, 2)}:${padZero(seconds, 2)}`;  
    
  return formattedDateTime;  
}  
  
// 辅助函数：用于在小于10的数字前面补0，以确保两位数格式  
function padZero(number, size) {  
  let s = number < 10 ? '0' : '';  
  return s + number.toString().substr(0, size);  
}

function getRandomInt(min, max) {  
    min = Math.ceil(min);  
    max = Math.floor(max);  
    return Math.floor(Math.random() * (max - min + 1)) + min;   
}

function touchmove(dom, callback) {
    //起始
    let startX;
    let startY;
    let startTime;
    // 结束
    let endX;
    let endY;
    let endTime;
    // 移动
    let moveX;
    let moveY;
    let moveTime;
    
    // 监听触摸开始
    dom.addEventListener("touchstart", (e) => {
        // 获取开始触摸的时间 X和Y的位置
        startTime = new Date().getTime();
        startX = Math.round(e.touches[0].screenX);
        startY = Math.round(e.touches[0].screenY);
    },);
    
    // 监听触摸结束
    dom.addEventListener("touchend", (e) => {
        // 结束触摸时间 X和Y离开的位置
        endTime = new Date().getTime();
        endX = Math.round(e.changedTouches[0].screenX);
        endY = Math.round(e.changedTouches[0].screenY);
        // 算一下触摸的 上下/左右 的距离
        moveX = startX - endX;
        moveY = startY - endY;
        moveTime = endTime - startTime;
        
        // 给个条件 上下/左右30px或者触摸时间超过 500ms 
        
        if (Math.abs(moveY) > 30 || Math.abs(moveX) > 30 || moveTime > 500) {
            // 判断方向 触发回调函数并把数据对象传回
            if (Math.abs(moveX) > Math.abs(moveY)) {
                //左右
                moveX > 0
                    ? callback({ direction: "right", to: 'left', value: moveX })
                    : callback({ direction: "left", to: 'right', value: Math.abs(moveX) });
            } else {
                //上下
                moveY > 0
                    ? callback({ direction: "down", to: 'up', value: moveY })
                    : callback({ direction: "up", to: 'down', value: Math.abs(moveY) });
            }
        }
    },);
}