javascript multiple OR conditions in IF statement

Question

I think I m missing something basic here  Why is the third IF condition true  Shouldn t the condition evaluate to false  I want to do something where the id is not 1  2 or 3   var id   1  if id    1    true     if id    1    false  if id    1    id    2    id    3    this returns true  why    Thank you

User · Answer

because the OR operator will return true if any one of the conditions is true  and in your code there are two conditions that are true

User · Answer

With an OR      operation  if any one of the conditions are true  the result is true   I think you want an AND   amp  amp   operation here

User · Answer

When it checks id  2 it returns true and stops further checking

User · Answer

Each of the three conditions is evaluated independently 1    id    1    false id    2    true id    3    true   Then it evaluates false    true    true  which is true  a    b is true if either a or b is true   I think you want  id    1  amp  amp  id    2  amp  amp  id    3   which is only true if the ID is not 1 AND it s not 2 AND it s not 3    1   This is not strictly true  look up short-circuit evaluation  In reality  only the first two clauses are evaluated because that is all that is necessary to determine the truth value of the expression

User · Answer

This is an example   false  amp  amp  true    true      returns true false  amp  amp   true    true     returns false  true    true    true      returns true false    true              returns true true    false              returns true

User · Answer

You want to execute code where the id is not  1 or 2 or 3   but the OR operator does not distribute over id   The only way to say what you want is to say     the id is not 1  and the id is not 2  and the id is not 3    which translates to  if  id     1  amp  amp  id     2  amp  amp  id     3    or alternatively for something more pythonesque   if    id in   1 2 3

[javascript] javascript multiple OR conditions in IF statement

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