Can you explain the purpose of this line in JavaScript?
config = config || {}
Can you explain the purpose of this line in JavaScript?
config = config || {}
config = config || {}
This code snippet is intended to set the variable config to an empty object {} if it has not been initialized yet, or if it has been initialized to one of the values listed below:
If config is currently equal to undefined, null, "", false, or 0, it will be reassigned the value of an empty object {}.
For example, consider the following scenarios:
var config = undefined; config = config || {}; //output Object {}
var config = null; config = config || {};//output Object {}
var config = 0; config = config || {}; //output Object {}
var config = false; config = config || {}; //output Object {}
var config = ""; config = config || {}; //output Object {}
Therefore, the OR condition is applied such that if the result of Boolean(config) is false (which occurs when config is one of the specified values: undefined, null, "", false, 0), then config is assigned the value of an empty object {}.
let settings = config || {}
This code snippet checks if the variable config is falsy (meaning it's either null, empty string, NaN, or undefined), and if so, sets the variable settings as an empty object. Otherwise, it assigns settings as the value of config.
let settings = config && {}
In this version, the code sets the variable settings as the value of config if it's not false, and if it's falsy, it assigns settings as an empty object instead.
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