错误：预期分配或函数调用，而是看到一个表达式

Question

booking.save(function (error, data) {
    error ? console.log(error) : res.redirect('/');
});

This code is causing the following error to be displayed in Sublime Text:

Expected an assignment or function call and instead saw an expression

Why is that? What is wrong with my code? It's working 100%. I don't see the error.

Answer 1

It is JSLint error not JS error.

In your case it considers that ternary operators should been used only for assignment such as

var foo = bar ? 2 : 3;

since there is no assignmet JSLint consider that string useless. Change it to if-else block or use JSHint with proper settings instead.

Answer 2

It expects the body of a function to be a list of statements. JSLint throws this warning because

error ? console.log(error) : res.redirect('/');

is an expession, not a statement. To make the warning go away, use an if...else statement instead.

if(err) console.log(error);
else res.redirect('/');