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#BASIC DATA STRUCTURES IN JAVA HOW TO#

We'll see more ways of handling arrays without modifying the original array one soon.Ĩ️⃣ Copy an Array with the Spread Operator Whereas methods like push() and splice() directly modify the original array. This feature of splice() of returning a new array instead of modifying the original array is very useful while dealing with arrays in React (in state to be precise) where it is strictly necessary that we should not modify the existing array. In effect, we have created a new array by extracting elements from an existing array, while the original array is untouched. 'hail' is not included), while weatherConditions would still have. TodaysWeather would have the value (we can see that element at index 3 i.e. Let weatherConditions = let todaysWeather = weatherConditions.

the second is the index at which to stop extraction ( extraction will occur up to, but not including the element at this index).

the first is the index at which to begin extraction, and.

Rather than modifying an array, slice() copies or extracts a given number of elements to a new array, leaving the array it is called upon untouched. Note that there can be any number of elements (separated by commas) following amountToDelete, each of which gets inserted.

the remaining arguments (13, 14) will be inserted starting at that same index.

the number of elements to be deleted (1), and.

The index at which to begin deleting elements (3),.

The second occurrence of 12 is removed, and we add 13 and 14 at the same index. splice ( startIndex, amountToDelete, 13, 14 ) console.

Splice()'s first parameter represents the index on the array from which to begin removing elements, while the second parameter indicates the number of elements to delete.Ĭonst numbers = const startIndex = 3 const amountToDelete = 1 numbers. And remember, arrays are zero-indexed, so to indicate the first element of an array, we would use 0.

The first two parameters of splice() are integers that represent indexes, or positions, of the array that splice() is being called upon. Splice() can take up to 3 parameters, but for now, we'll focus on just the first 2. splice() allows us to do just that: remove any number of consecutive elements from anywhere in an array.

#BASIC DATA STRUCTURES IN JAVA HOW TO#

So far we've learned how to remove elements from the beginning and end of arrays using shift() and pop(), but what if we want to remove an element from somewhere in the middle? Or remove more than one element at once? Greetings would have the value, and popped would have the value hello.