Assignments of values in Javascript

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I am starting my studies in JS and I have the following question. Consider the code below:

const vazio = null
const resultado = vazio || 'Anonimo'

console.log(resultado)

The console output will be the 'Anonimo' string display'.

I know that null values are considered false, but I didn’t understand the JS behavior of assigning the string 'Anonimo' to the constant result. I thought it would convert the string 'Anonimo' to Boolean(true) and assign to the constant result the boolean comparison: false || true = false.

Because this behavior of the JS?

Thanks for your attention

javascript

  • || is a logic operator and not a means of "conversion", I recommend you read What are Truthy and falsy values? - I recommend reading: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators

  • Hi William, thank you for the content, very enlightening... But in it there is no specific example similar to the example I quoted and could not abstract with the content indicated.

  • 1

    Oi Bruno. The || operator will not convert to true or false, the second value after || is the alternative to the first value before ||, which does not need to be exactly false, it can be "falsy" (are falsy values like null, Undefined, Number -0 or +0 and Nan), ie will not "convert", will deal within Truthy or falsy, being the value after || assigned only if the value before is falsy... Yet if I did const resultado = !!(vazio || 'Anonimo') you would have a Boolean result, read: https://answall.com/q/29014/3635

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