javascript - use existing variable in for loop - Stack Overflow

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Is it possible to leave out the variable assignment from a for loop and do something like this…?

otherVar = 3;

for ( otherVar > 0; otherVar-- )
{
    stuff
}

Is it possible to leave out the variable assignment from a for loop and do something like this…?

otherVar = 3;

for ( otherVar > 0; otherVar-- )
{
    stuff
}

• javascript
• loops
• for-loop

Share Improve this question Follow asked May 23, 2012 at 3:23 EssentialEssential 42177 silver badges1414 bronze badges 1

• 1 You can also declare a bunch of vars right in the loop: for(var someVar=0, otherVar=3, yetAnother='bob';yetAnother!==false;someVar++) – Erik Reppen Commented May 23, 2012 at 3:42

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3 Answers 3

Sorted by: Reset to default 16

Yes, but you need to put in the semi-colon:

var otherVar = 3;

for ( ; otherVar > 0; otherVar-- ) {
    doStuff();
}

Usually While is more popular for this situation (better readability)..

otherVar = 3;

while ( otherVar > 0)
{
   stuff
   otherVar--;
}

You can count down from any arbitrary number:

var counter = 3;
while ( counter-- ) {
  console.log( counter );
}

Which outputs: 2, 1, 0

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