I'm adding ESLint to my Node project and cannot figure out how to change this code to work properly:

const connection = {};

for (let [prop, value] of connectionString) {
  prop = prop.split(' ')[0];
  connection[prop] = value;
}

I'm getting error:

'value' is never reassigned. Use 'const' instead.

I'm adding ESLint to my Node project and cannot figure out how to change this code to work properly:

const connection = {};

for (let [prop, value] of connectionString) {
  prop = prop.split(' ')[0];
  connection[prop] = value;
}

I'm getting error:

'value' is never reassigned. Use 'const' instead.

• javascript
• ecmascript-6
• eslint

1 Answer 1

Rather than reassigning prop, create a new variable for the first word. That way, both prop and value can be declared with const:

const connection = {};
for (const [prop, value] of connectionString) {
  const firstWord = prop.split(' ')[0];
  connection[firstWord] = value;
}

Most of the time, clean readable code can work just fine without ever reassigning a variable. Best to only reassign an existing variable when you absolutely have to - that's a big part of why the rule exists, to prod you to use const (and produce more readable code as a result).

You could also achieve it without the intermediate variable:

const connection = {};
for (const [prop, value] of connectionString) {
  connection[prop.split(' ')[0]] = value;
}