JS How to set values outside scope with single line

Question

if the function calculateAvgGainLoss response includes avgGain, avgLoss we can get these values like this.

const { avgGain, avgLoss } = calculateAvgGainLoss(prices);

I want to set these values to the variable that defined outside of the function. How can I do that ? Example below.

describe("test", () => {
  let avgGain: number, avgLoss: number;
  it("Calculate average gain & loss", () => {
    const prices = [...];
    /*...This isn't working, has to be changed...*/ { avgGain, avgLoss } = calculateAvgGainLoss(prices);
    expect(avgGain).toBe(0.24);
    expect(avgLoss).toBe(0.1);
  });

});

score 2 · Accepted Answer · answered Jan 17 '20 at 13:59

2

Beginning the line by a { confuses parsers (is it the beginning of a scope? an object? etc). Just bypass this by wrapping your line with parenthesis:

describe("test", () => {
  let avgGain: number, avgLoss: number;
  it("Calculate average gain & loss", () => {
    const prices = [...];
    ({ avgGain, avgLoss } = calculateAvgGainLoss(prices)); // <--
    expect(avgGain).toBe(0.24);
    expect(avgLoss).toBe(0.1);
  });

});

answered Jan 17 '20 at 13:59

Nino Filiu

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Actually I had tried exactly this way before asking but this time I am getting ' Variable '.....' is used before being assigned' error. – Caner Sezgin Jan 17 '20 at 14:01
1

I don't understand - please provide a [typescript playground](https://www.typescriptlang.org/play/) link – Nino Filiu Jan 17 '20 at 14:03
1

It worked as expected. My mistake sorry. Thank you for your help – Caner Sezgin Jan 17 '20 at 14:08

JS How to set values outside scope with single line

1 Answers1