# 好用的函式分享(持續更新)
## 建立時間戳

var timestamp = new Date().getTime();

## 時間戳的轉換
- `time` 時間戳

function changeDate(time) {
	let date = new Date(parseInt(time));
	Y = date.getFullYear() + '-';
	M = (date.getMonth() + 1 < 10 ? '0' + (date.getMonth() + 1) : date.getMonth() + 1) + '-';
    // 判斷如果天數小於10，前面會加0
	D = date.getDate() < 10 ? '0' + date.getDate() + ' ' : date.getDate()+' ';
	h = date.getHours() + ':';
	m = date.getMinutes() + ':';
	s = date.getSeconds();
	let new_date = Y + M + D + h + m + s;
	return new_date;
}
let value = changeDate(1690214400000) 
console.log(value) // 2023-07-25 0:0:0

## 六位數字序號編碼
- `num` 數字

function serialNum(num) {
	let member = "000000";
	let Num = String(num).length;
	let Data;
	if (num <= 5) {
		Data = member.slice(0, -1).concat(num);
	} else {
		Data = member.substr(Num, num).concat(num);
	}
	return Data;
}
let value = serialNum(5);
console.log(value) // 000005

## 陣列轉換物件
- `formdata` 陣列

function serializeObject(formdata) {
	var o = {};
	$.each(formdata, function () {
		if (o[this.name] !== undefined) {
			if (!o[this.name].push) {
				o[this.name] = [o[this.name]];
			}
			o[this.name].push(this.value || '');
		} else {
			o[this.name] = this.value || '';
		}
	});
	return o;
};
let data = [{name:'Name',value:'Linda'}]
let value = serializeObject(data);
console.log(value) // { Name:'Linda' }

## 每三位數加逗號
- `num` 價格 / 數字

function toThousands(num) {
	var result = [], counter = 0;
	num = (num || 0).toString().split('');
	for (var i = num.length - 1; i >= 0; i--) {
		counter++;
		result.unshift(num[i]);
		if (!(counter % 3) && i != 0) { result.unshift(','); }
	}
	return result.join('');
}
let value = toThousands(5230);
console.log(value) // 5,230

## GUID碼的產生

function RandomID() {
	let _ID = ([1e7] + -1e3 + -4e3 + -8e3 + -1e11).replace(/[018]/g, c =>
		(c ^ crypto.getRandomValues(new Uint8Array(1))[0] & 15 >> c / 4).toString(16)
	);

	return _ID ;
}
let value = RandomID();
console.log(value) // 960ed819-ae75-4612-8be6-3f06ab9cf4df

## 超過字數隱藏

function removeText() {
    var len = 100; // 上限是多少字
    $("選取的元素").each(function (i) {
        if ($(this).text().length > len) {
            // 如果大於上限會跑進來這邊
            var text = $(this).text().substring(0, len - 1) + "...";
        }
    });
};

## 日期選取比較
- 當選取的日期超過當日日期，回傳當日日期

function consoleDate() {
    $("選取的元素").on("change", (e) => {
        let chooseDay = $(e.target).val; // 2023-07-25
        let today = changeDate(+ new Date()).split(" ")[0]; // 2023-07-28
       
        if (chooseDay.replace(/\-/g, "/") > today.replace(/\-/g, "/")) {
            // 把 "-" 拿掉換成通用比較格式 "/"
            document.getElementById("選取的元素IDName").value = today;
            or 
            $("選取的元素").val(today);
           
        } 
    });
}
consoleDate();

## ES6 快速排除重複的Object

function setObject(data){
    let set = new Set();
    let _data = data.filter(item => !set.has(item.name) ? set.add(item.name) : false);
    
}
let formData = [{name:'yoyo',year:'18'},{name:'yoyo',year:'20'}];
setObject(formData)
console.log(setObject(formData)) //  [{name:'yoyo',year:'18'}]

## 擷取網址資料

let url = location.href;
if (url.indexOf('?') != -1) { // 判斷有沒有資料
    url = url.toString().replace("#", "?");
    let s_Id = url.replace("&", "?").split('?')[1];
    StoreId = s_Id.split('=');
}

## 判斷瀏覽器是關閉還是重整

let _beforeUnload_time = 0, _gap_time = 0;
let is_fireFox = navigator.userAgent.indexOf("Firefox") > -1;//是否為火狐瀏覽器
window.onunload = function () {
    // 計算網頁時間
    _gap_time = new Date().getTime() - _beforeUnload_time;

    if (_gap_time <= 5)
        //瀏覽器關閉
        returnOrderId(MerchantTradeNo);
    else
        //瀏覽器重整
        return;
}
window.onbeforeunload = function () {
    _beforeUnload_time = new Date().getTime();
    if (is_fireFox)//火狐瀏覽器關閉
        returnOrderId(MerchantTradeNo);
};

## 計算數值轉換成想要的格式
###### [資料來源](https://stackoverflow.com/questions/10756313/javascript-jquery-map-a-range-of-numbers-to-another-range-of-numbers)

function scale (number, inMin, inMax, outMin, outMax) {
    return (number - inMin) * (outMax - outMin) / (inMax - inMin) + outMin;
}

## 隨機顏色

function randomColor() {
    let red = Math.floor(Math.random() * 256); 
    let green = Math.floor(Math.random() * 256);
    let blue = Math.floor(Math.random() * 256);

    let color = "rgb(" + red + ", " + green + ", " + blue + ")";
    
    return color;
}
console.log(randomColor());

---

##### ヽ(∀ﾟ )人(ﾟ∀)人( ﾟ∀)人(∀ﾟ )人(ﾟ∀)人( ﾟ∀)ﾉヽ(∀ﾟ )人(ﾟ∀ﾟ)人( ﾟ∀)人(∀ﾟ )人(ﾟ∀ﾟ)人( ﾟ∀)人(∀ﾟ )人( ﾟ∀)人

##### 以上 如果註解哪裡有錯誤或有問題，歡迎提出來一起討論~~~~