CODEWITHSUNDEEP
javascript
franchyze923
franchyze923

Reputation: 1200

Why does the iterator in a JavaScript for loop not need a semicolon?

I'm curious why when making a for loop in JavaScript a ; is not necessary after the i++ statement? It tripped me up. It actually doesn't even work if you include a semicolon after the iterator statement.

e.g.

    for(var x=1; x<100; x++){

        document.write(x);
    }

Upvotes: 0

Views: 103

Answers (1)

Tom M
Tom M

Reputation: 2904

While tokenizing the code for compiling, the JS-parser usually knows where statements start and end due to Automatic Semicolon Insertion.

In the case of a for-loop however, semicolons are interpreted as a separator of statements. For-Loops accept up to three "parameters". If you put in a semicolon, a fourth one will be expected and it will throw an error.

The final-expression-statement of a for-loop is terminated by ).

This control-structure behaves similar to PHP, C, Java and C++

thanks to @Antoniu Livadariu for mentioning this in the comments

Further Information

Upvotes: 1

Related Questions