I watch the video course "programming lessons" from loftblog, the theme is cycles. Faced a problem - I completely rewrite the code itself, as in the video. Everything works for them, for me, no. Here is the code:

var arr = [1,2,3,4,5]; for(i=0; sum=0; i<arr.length; i++) { sum+=arr[i]; }; console.log(sum);

this is what the console issues:

 "SyntaxError: Unexpected token ; at https://static.jsbin.com/js/prod/runner-4.1.4.min.js:1:13924 at https://static.jsbin.com/js/prod/runner-4.1.4.min.js:1:10866"

in the comments to the video a few more people write that this code does not work for them. What is the problem?

Closed due to the fact that off-topic participants andreymal , 0xdb , Grundy , ߊߚߤߘ , dlarchikov Aug 20 '18 at 8:29 .

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    2 answers 2

    Replace the semicolon with a comma:

     for(i=0, sum=0; i<arr.length; i++)
    • thank! I really didn't notice, although I looked at the code several times - Guest

    First, in the loop, forgot var in the declaration of the variable.

    Secondly, the parameters need to be separated by a comma.

    Thirdly, this is a recommendation, incorrect work with the scope in the code. sum must be declared before the loop.

     var arr = [1, 2, 3, 4, 5]; var sum = 0; for (var i = 0; i < arr.length; i++) { sum += arr[i]; } console.log(sum);
    • Thanks, I really didn’t carefully rewrite the code, but declaring variables wasn’t necessary, although I tried it too, but the problem was precisely in commas - Guest