SyntaxError: Illegal return statement (V8-based)
SyntaxError: return not in function (Firefox)
SyntaxError: Return statements are only valid inside functions. (Safari)

SyntaxError.

A return or yield statement is called outside of a function. Maybe there are missing curly brackets somewhere? The return and yield statements must be in a function, because they end (or pause and resume) function execution and specify a value to be returned to the function caller.

function cheer(score) {
  if (score === 147)
    return "Maximum!";
  }
  if (score > 100) {
    return "Century!";
  }
}

// SyntaxError: return not in function

The curly brackets look correct at a first glance, but this code snippet is missing a { after the first if statement. Correct would be:

function cheer(score) {
  if (score === 147) {
    return "Maximum!";
  }
  if (score > 100) {
    return "Century!";
  }
}

• return
• yield