The concat() method preserves empty slots if any of the source arrays is sparse. It does not alter this or any of the arrays provided as arguments but instead returns a shallow copy that contains the same elements as the ones from the original arrays. The concat method does not recurse into nested array arguments. Then, for each argument, its value will be concatenated into the array - for normal objects or primitives, the argument itself will become an element of the final array for arrays or array-like objects with the property Symbol.isConcatSpreadable set to a truthy value, each element of the argument will be independently added to the final array. The array will first be populated by the elements in the object on which it is called. Object.prototype._lookupSetter_() Deprecated.Object.prototype._lookupGetter_() Deprecated.Object.prototype._defineSetter_() Deprecated.Object.prototype._defineGetter_() Deprecated.

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It duplicates the value of strings and numbers to the new array.Ĭonsole.

(For instance, a nested array) As a result, any modifications to the referenced object are reflected in the newly returned array.

References to objects are copied to the new array.The array's elements are shallowly copied using the slice() function as follows: slicing the array from start to second-to-lastĮxample 3: Objects as Array Elements in JavaScript's slice() The final element's index is -1, the next-to-last element's index is -2, and so on.Ĭonst languages = You may also use negative start and end indices with JavaScript. log(new_arr2) // Įxample 2: Negative index slice() in JavaScript slicing from the second element to fourth elementĬonsole.

ExamplesĮxample 1: The slice() function in JavaScript. Returns a new array that contains the elements that were removed. The selection stops at the final element's index if it is not given.

end (optional) - The selection's final index (exclusive).

Unless otherwise specified, the selection begins at start 0.

start (optional) - The selection's initial index.

The slice() method's syntax is as follows:

Array slice in javascript