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Discard a variable in a JavaScript object spread by assigning it to _

I had some code with spread syntax where some variables were being captured and used, and others were being saved into a catchall props variable.

There was a variable I wanted to discard – not capture and use, and not add to props. I could just capture it and not use it, but it might be flagged as an unused variable.

Here’s a simple example, where I capture the name variable and discard lastRoll:

const shape = {
  name: 'd20',
  sides: 20,
  color: 'red',
  lastRoll: 7,
};

const { name, lastRoll: _, ...diceProps } = shape;

console.log(name);
// 'd20'

console.log(diceProps);
// { sides: 20, color: "red" }