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I guess some of this knowledge is helpful or necessary for people who want to know JS inside-out. Nevertheless, none of that code looked like anything a program

I guess some of this knowledge is helpful or necessary for people who want to know JS inside-out. Nevertheless, none of that code looked like anything a programmer would write if they respected readability and conveyance of code. Maybe I'm just taking things too seriously here... A code snippet like the following wouldn't make me ask how it works, but it would make me want to find the person responsible for putting this snippet in production code: var num1 = 5, num2 = 10, result = num1+++num2; (I'm probably thinking in this manner these days because I'm currently in a situation where I'm maintaining someone else's code instead of building something.)

deleted 14y ago
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prophetjohn 14y ago
The above example is at least academically interesting since you can reason through it with a bit of programming experience and intuition about operator precedence. Does plus or pre/postfix increment have higher precedence? Probably increment. Does prefix or postfix have higher precedence? They're probably the same -> evaluate from left-to-right. Code is equivalent to num1++ + num2; But the examples like "what is the difference between substring() and substr()", "What is the lowest cross-browser increment that [setInterval()/setTimeout()] can accurately use" is just trivia and is boring.
- jonsen 14y ago
  You also need to know how tokens are produced by lexical analysis. It could have produced: 'num1' '+' '++' 'num2' In fact it produces 'num1' '++' '+' 'num2' so it's not about evaluate from left-to-right.
  - prophetjohn 14y ago
    Is there a case in JavaScript where operators with the same precedence are not evaluated left-to-right?
    - jonsen 14y ago
      I don't know. But I happen to know that the javascript tokenizer matches the longest possible substring. Therefore it takes '++' from '+++..', not '+'. It's not about precedence. EDIT: Yes, the assignment operators, =, += etc., evaluates right to left.

deleted 14y ago

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prophetjohn 14y ago

The above example is at least academically interesting since you can reason through it with a bit of programming experience and intuition about operator precedence. Does plus or pre/postfix increment have higher precedence? Probably increment. Does prefix or postfix have higher precedence? They're probably the same -> evaluate from left-to-right. Code is equivalent to num1++ + num2; But the examples like "what is the difference between substring() and substr()", "What is the lowest cross-browser increment that [setInterval()/setTimeout()] can accurately use" is just trivia and is boring.

jonsen 14y ago
You also need to know how tokens are produced by lexical analysis. It could have produced: 'num1' '+' '++' 'num2' In fact it produces 'num1' '++' '+' 'num2' so it's not about evaluate from left-to-right.
- prophetjohn 14y ago
  Is there a case in JavaScript where operators with the same precedence are not evaluated left-to-right?
  - jonsen 14y ago
    I don't know. But I happen to know that the javascript tokenizer matches the longest possible substring. Therefore it takes '++' from '+++..', not '+'. It's not about precedence. EDIT: Yes, the assignment operators, =, += etc., evaluates right to left.