最新消息:雨落星辰是一个专注网站SEO优化、网站SEO诊断、搜索引擎研究、网络营销推广、网站策划运营及站长类的自媒体原创博客

How is division before multiplication in Javascript? - Stack Overflow

programmeradmin5浏览0评论

I run some code and I get same results with or without parenthesis, even if I know that multiplication have higher precedence then division. Here is example:

let calculate = 16 / 30 * 100

I gott same result as

let calculate = (16 / 30) * 100

So I don't know which of them has higher precedence.

I run some code and I get same results with or without parenthesis, even if I know that multiplication have higher precedence then division. Here is example:

let calculate = 16 / 30 * 100

I gott same result as

let calculate = (16 / 30) * 100

So I don't know which of them has higher precedence.

Share Improve this question asked May 14, 2018 at 14:43 ZeroZero 715 bronze badges 11
  • 7 "even if I know that multiplication have higher precedence then division" that's a pretty big assumption. Multiplication and division have the same priority, and they associate left-to-right. See here – Federico klez Culloca Commented May 14, 2018 at 14:45
  • 1 About operator precedence in JS – Gabriel Carneiro Commented May 14, 2018 at 14:46
  • 1 @MátéSafranka - It's better written vertically. It's really (PE)(MD)(AS). – T.J. Crowder Commented May 14, 2018 at 14:48
  • 2 There's something deeply ironic about the mnemonic acronym for operator precedence needing parentheses. – Máté Safranka Commented May 14, 2018 at 14:50
  • 1 @TJWolschon - Yeah, I understand PEMDAS is more U.S., BODMAS more UK. My ment above should have been "For Brits:" not "For Americans:" (I'm both, so I get confused sometimes.) – T.J. Crowder Commented May 14, 2018 at 14:55
 |  Show 6 more ments

2 Answers 2

Reset to default 8

So I don't know which of them has higher precedence.

Neither, they have the same precedence and associativity; see MDN's page for details.

Almost all programming languages adhere to PEMDAS:

  • PE - Parentheses and Exponents
  • MD - Multiplication and Division
  • AS - Addition and Subtraction

...aka BODMAS:

  • BO - Brackets and Orders
  • DM - Division and Multiplication
  • AS - Addition and Subtraction

See this fiddle: https://www.w3schools./code/tryit.asp?filename=FRB0CCQOKZT2

the code is evaluated in this order:

  • Parentheses
  • Multiply and Divide
  • Addition and Subtraction

If you have Multiple and Divide in the same equation then it evaluates the first one it encounters. you can override this by using parentheses.