Javascript的數學難題
首先先考大家幾個數學題，如果這幾題的答案你都能順利的回答，那恭喜你！你可以安心地閱讀這篇文章，你一定能看懂！
題目ㄧ. 0.1 + 0.2 = ？
題目二. 1 – 0.9 = ？
題目三. 0.69 x 10 = ？
相信上面三個簡單的十進位數學運算，你的答案應該會跟我一樣吧？
第一題. 0.3
第二題. 0.1
第三題. 6.9
上面應該是無庸置疑的答案，但是如果我們把這三個題目丟給Javascript去運算之後，得到的結果會變成這樣：
第一題. 0.1 + 0.2 = 0.30000000000000004
第二題. 1 – 0.9 = 0.09999999999999998
第三題. 0.69 x 10 = 6.8999999999999995
什麼！？Javascript連這種小學生的算術都會算錯嗎？其實是有原因的，Javascript所有數字都是以64位浮點數形式儲存，也就是所有的數字都會變轉換成二進位。
上面題目中特別有提到這是3個十進位的數學運算，這也就是這個題目的重點，如果今天的題目改成：10 / 3 = 3.3333333333333334 也許你就能比較明白了，也就是說在十進位中要表達 1 / 3 和二進位中表達 1 / 10 一樣困難。
但其實在我們設計網頁的過程中，使用者是沒有二進位觀念的，只在乎運算出來的數值是否符合十進位的結果，這個時候我們可以利用一些技巧來達成正確的結果。
方法1 . 將小數變成整數後再進行運算
第一題. ((0.1 x 10) + (0.2 x 10)) / 10 = 0.3
第二題. ((1 x 10) – (0.9 x 10)) / 10 = 0.1
第三題. ((0.69 x 100) x 10 / 100) = 6.9
雖說以上的方法能夠順利完成任務，但若運算的數值是動態（Dynamic）的，乘數的部分就比較難下，所以我們可以採用第二種方法。
方法2. Math.js（https://mathjs.org/）
透過網站上提供的js，或是透過CDN（https://cdnjs.com/libraries/mathjs）來引入後，透過以下的方法，就可以正確計算出上面三個題目的結果，其中14指的是精準度，通常已經很夠用了。
第一題. math.format(0.1 + 0.2 , 14) = 0.3
第一題. math.format(1 – 0.9 , 14) = 0.1
第一題. math.format(0.69 x 10 , 14) = 6.9
其實Math.js還有很多好用的功能，可以到它官方的網站閱讀一些文章，基本上所有的數學運算應該都可以透過它來玩完成。
Тут можно приобрести создание сайта для медицинского центра создание сайтов для медицины
Legit online Mexican pharmacy: Cert Pharm – Best Mexican pharmacy online
new year yacht party dubai yacht rental dubai marina
Cert Pharm Legit online Mexican pharmacy Best Mexican pharmacy online
https://certpharm.com/# mexican pharmacy
https://certpharm.com/# Best Mexican pharmacy online
mexico drug stores pharmacies: mexican online pharmacies prescription drugs – Best Mexican pharmacy online
mexican pharmacy online: mexican pharmacy online – Legit online Mexican pharmacy
Hidden World War II tunnels to open to public
военный адвокат Запорожье
In this week’s roundup of travel news: Denver’s weed church, zodiac predictions for the Year of the Snake, plus what promises to be London’s most ambitious – and deepest – new visitor attraction.
Going underground
Some 30 meters (98 feet) below central London lies a mile-long network of tunnels that is set to be the UK capital’s glitziest new tourist attraction, according to the company that’s secured planning approval for the $149 million transformation.
The Kingsway Exchange Tunnels were built in the 1940s to shelter Londoners from the Blitz bombing campaign during World War II. That was the last time they were open to the general public. Their next wartime role was as the home of Britain’s top-secret Special Operations Executive, an offshoot of MI6 and the real-life inspiration for James Bond’s Q Branch.
The new attraction will be a memorial to the Blitz, which Angus Murray, chief executive of the London Tunnels, told Reuters will be part museum, part exhibition and part entertainment space.
The plan is to open to the public by late 2027 or early 2028. Read more here in our earlier story announcing the project.
If you can’t wait until then to get down in the city’s bowels, London Transport Museum runs exclusive guided tours of its abandoned tube stations, including Down Street, a secret underground bunker that helped win World War II.
Year of the Snake
The first new moon of the lunar calendar fell on January 29, ushering in the Year of the Snake and the 15-day Spring Festival, a big annual highlight in China and for Chinese communities around the world.
Here’s our guide to what it all means and, whether you’re a horse, goat, monkey, rooster or any other sign in the Chinese zodiac, here’s what the stars say are your predictions for the year ahead.
Food is, of course, a key part of the celebrations. One of the most fun elements is the “prosperity toss,” kind of like a food fight with chopsticks but seasoned with auspicious blessings for the year ahead.
For the culinarily adventurous, 2025 is a good time to visit Hong Kong and see how restaurants serve snake. Delights include snake balls and snake soup – and be sure to leave room for the penis wine. Watch here.
Тут можно приобрести заказать сайт клиники создание сайта медицинского центра
buying prescription drugs in mexico online https://certpharm.shop/# Mexican Cert Pharm
1 hour yacht ride dubai yacht private
‘I’m very impulsive’: Why this American woman moved to France at the age of 70
жесткое порно
She’d dreamed of living in France for years, but according to Janice Deerwester, originally from Texas, life always seemed to get in the way.
In 2021, Janice, who has been a widow since 2012, found herself lying on her bed with the lyrics to “Is That All There Is?,” a song about dissatisfaction that was a hit for country singer Peggy Lee back in 1969, playing in her head.
“I hated that song when it came out, but all of a sudden it came to my mind,” Janice, who was based in Georgia at the time, tells CNN Travel. “I thought, ‘Is this all there is?’ I work, come home tired. I get up. Is this it?”
Realizing that she wanted more from life, Janice decided there and then that she would relocate to Fontainebleau — the French town she’d had her heart set on since a 2018 visit. Less than a year later, at the age of 70, she did just that.
“I’m very impulsive so that kind of followed the rule,” she adds.
Now happily settled in Fontainebleau, located southeast of Paris, Janice feels that she “made the best choice ever” and is incredibly grateful to be living out her fantasy.
“I am the luckiest woman I feel that ever was,” she says. ”And why I have this, and why I was given this, I have no idea. But I’m just blessed every day that I get to live here.”
Janice goes on to explain that she wasn’t necessarily unhappy back in Georgia, and enjoyed living on a horse ranch in the country, which she had been renting since selling her home, but was overcome with the feeling that “there’s got to be more” to life.
UTLH:??????????????????????????????,??????????????????????????,??????????????????????????????????????UTLH ??????“??”??,????????????,??????,??????????????????????????1. UTLH — ???????????1.1. ????(UFA)????????????????????,UTLH ?:?????????????????????:????????????,????????????1.2. UTL Club ?????????????????,UTLH ?????????????,???????????????????:?????,??????????????????2. ?????:???????????2.1. ???????? 957,315 ? UTLH ??,?????????????????????,????????“??”????2.2. ??????????????????????????? UTLH ???????????????????????????????3. Staking:?????,???3.1. ?? 24%(?? 2%)?????:?????? UTLH ??? staking ?,????????????????????:? 1 ?????????,????????????????????3.2. ???????Binance Smart Chain(BSC)?????????????????????:staking ????,???????????????4. ????:???????4.1. UTLH ??,?????????? UTLH ????,??????????????????:???????????????????????????????4.2. ??????????????,??????????????,???????,??????????5. ????:Binance Smart Chain (BSC)5.1. ????????????“???”????,BSC ??????????? staking UTLH,???????5.2. ?????????UTLH ????? DEX(? PancakeSwap)??? DeFi ???????????????????,????????????6. ???????6.1. ??????????????,UTLH ????????????:????(UFA)???????????Staking ??????????,?????,????????6.2. ?????????????????????????????,?????????,???????????????????????,? UTLH ??????????????7. ??????????? BSC ??(? MetaMask ? Trust Wallet)???????????????????? UTLH??? staking:24%?????????????????????????:????????????????????,UTLH ??????????????,??????????UTLH ????????????????????????????????????????????????? staking????????????????(Binance Smart Chain),UTLH ????????????????????????????????????????????,????????????,???????????????——UTLH ??????????????????????
https://certpharm.com/# mexican pharmacy online
buying prescription drugs in mexico: Mexican Cert Pharm – Cert Pharm
medicine in mexico pharmacies: Legit online Mexican pharmacy – Cert Pharm
п»їbest mexican online pharmacies http://certpharm.com/# Cert Pharm
buying from online mexican pharmacy: Cert Pharm – Mexican Cert Pharm
rent private yacht dubai yacht cruise
http://certpharm.com/# pharmacies in mexico that ship to usa
Тут можно преобрести заказать сайт клиники разработка сайт медицинского центра
Balanceo dinamico
Sistemas de calibracion: fundamental para el rendimiento uniforme y eficiente de las dispositivos.
En el entorno de la tecnologia avanzada, donde la eficiencia y la fiabilidad del equipo son de maxima importancia, los equipos de equilibrado tienen un funcion vital. Estos sistemas especificos estan disenados para equilibrar y estabilizar componentes dinamicas, ya sea en equipamiento manufacturera, transportes de transporte o incluso en aparatos de uso diario.
Para los profesionales en conservacion de aparatos y los profesionales, trabajar con dispositivos de balanceo es crucial para garantizar el funcionamiento estable y seguro de cualquier mecanismo giratorio. Gracias a estas herramientas modernas avanzadas, es posible reducir sustancialmente las oscilaciones, el estruendo y la esfuerzo sobre los rodamientos, mejorando la duracion de componentes importantes.
De igual manera trascendental es el papel que cumplen los dispositivos de equilibrado en la soporte al usuario. El soporte especializado y el soporte permanente empleando estos sistemas habilitan brindar prestaciones de optima nivel, mejorando la bienestar de los usuarios.
Para los duenos de negocios, la inversion en sistemas de ajuste y medidores puede ser esencial para optimizar la productividad y desempeno de sus equipos. Esto es sobre todo relevante para los emprendedores que dirigen reducidas y medianas empresas, donde cada punto es relevante.
Por otro lado, los dispositivos de balanceo tienen una vasta utilizacion en el ambito de la seguridad y el monitoreo de nivel. Habilitan localizar posibles problemas, reduciendo reparaciones elevadas y averias a los equipos. Tambien, los informacion extraidos de estos equipos pueden aplicarse para mejorar procesos y mejorar la presencia en plataformas de busqueda.
Las zonas de utilizacion de los dispositivos de balanceo cubren numerosas areas, desde la produccion de transporte personal hasta el control del medio ambiente. No afecta si se considera de extensas producciones productivas o reducidos espacios hogarenos, los sistemas de balanceo son fundamentales para proteger un funcionamiento eficiente y sin riesgo de fallos.
buying prescription drugs in mexico https://certpharm.shop/# mexican pharmacy
https://certpharm.shop/# mexican rx online
Тут можно преобрести разработка сайтов медицинских центров разработка сайта для медицинской организации
Тут можно преобрести разработка сайта для медицинской организации создание сайта медицинского центра
mexican pharmacy online: mexican pharmacy – Legit online Mexican pharmacy
Тут можно преобрести создание сайтов для медицинских организаций разработка сайтов медицинских центров
https://certpharm.com/# Cert Pharm