The comma operator (,
) evaluates each of its operands (from left to right) and returns the value of the last operand. This lets you create a compound expression in which multiple expressions are evaluated, with the compound expression's final value being the value of the rightmost of its member expressions.
(c) MDN
🐊Putout plugin adds ability to extract sequence expressions. Check out in 🐊Putout Editor.
☝️Remember, when you writing a transform you can skip all parts related to extracting sequence expressions and just reuse current plugin it will make your code simpler and less error prone.
Install
npm i @putout/plugin-extract-sequence-expressions -D
Rule
{
"rules": {
"extract-sequence-expressions": "on"
}
}
❌ Example of incorrect code
module.exports.x = 1,
module.exports.y = 2;
fn((a, b));
fn(a), 'hello';
✅ Example of correct code
module.exports.x = 1;
module.exports.y = 2;
fn(a, b);
fn(a, 'hello');
Comparison
License
MIT