JavaScripts magic three dots

The so called spread / rest operator scares a lot of people switching to JavaScript. This should be a self exaplaining code snippet: const obj1 = { key1: 1, key2: 2 }; const obj2 = { ...obj1, key3: 3 }; console.log(obj2); // output: { key1: 1, key2: 2, key3: 3 } const obj3 = { ...obj1, key2: 4, key3: 3 }; console.log(obj3) // output: { key1: 1, key2: 4, key3: 3 } // keys will be overridden const arr1 = [ 1, 2, 3, 4 ]; const arr2 = [ ...arr1, 5, 6 ]; console.log(arr2); // output: [ 1, 2, 3, 4, ...

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