![]() ![]() Next up, we can also remove elements from an array based on a condition and not just on an index with the use of Array.filter: let arr = Ĭonst newArr = arr.filter((el) => el > 2)ĭifferently from Array.pop, Array.shift and Array.splice, Array.filter creates a new array with all the elements that pass the condition in the callback function so your original array won’t get modified as you can see from the code above. const arr = Īs you can see, in the first example we specified 1 as the number of elements to remove, whereas in the second example we didn’t pass any argument thus removing all items in the array from our starting index.Īrray.splice will modify your original array and return the removed elements so you can do the following: const arr = We can provide a second argument to specify how many elements to delete. Now we will look at a couple of ways to remove a specific element from an array.įirst, let’s look at Array.splice used in combination with Array.indexOf.Īrray.splice allows us to remove elements from an Array starting from a specific index. No additional arguments are allowed, so you can see that these methods are fairly basic.īoth methods will modify your origianl array and both return the removed element so you can do the following: const arr = Let’s say we are not interested in replacing a value but we just want to remove it, we will now look at different ways of doing so.įirst, let’s look at the more basic methods to remove values from an Array: Array.pop and Array.shift const arr = Īrray.pop will remove the last element of the Array while Array.shift will remove the first one. Pretty easy right? Using findIndex we can also check scenarios like the following where we have an Array of Objects: const arr = [Ĭonst index = arr.findIndex((el) => el.id = 2)Īs you can see, using findIndex we can easily find and then replace Objects in an Array of Objects. We can do the same using findIndex: const arr = Ĭonst index = arr.findIndex((el) => el = 2) ![]() In order to replace an element we need to know its index, so let’s see some examples using the methods we just learned: const arr = Īss you can see, first, we got the index of the element we wanted to change, in this case, the number 2 and then we replaced it using the brackets notation arr. Knowing the methods above, it couldn’t be easier! ![]() Now that we know how to check if the Array includes a specific element, let’s say we want to replace that element with something else. Learn Now Replacing an element of an Array at a specific index Next up are two new metho introduced in ES6 (ES2015): const arr = Īrray.some will check if at least one value in the array matches the condition in our callback function and Array.every will check that ALL of the elements in the Array match that condition. Similarly to all the methods we previously saw, you can also define a starting index where to start check the Array. The difference between the two methods is the same as the one we saw between Array.includes and Array.find, where the first one ( Array.indexOf) will accept a value to check whereas the second one ( Array.findIndex) will accept a callback to perform more advanced checks. These methods are useful because they can be used to both checks if an element exists in the Array while at the same time getting a reference as to where that element is positioned, which we can use to then replace that said element. To check if an element exists, we simply need to check if the returned value is -1 or not. !!arr.find((a) => a > 2 & a el = 1) != -1Īrray.indexOf and Array.findIndex are similar because they both return the index of the first matching element found in our Array, returning us -1 if it’s not found. It’s a more powerful method compared to Array.includes as we can pass a callback to it, not just a value to check, meaning that we can do more complex checks such as: const arr = This method will return the value itself or undefined if no value is found so we can use the !! operator to convert the result to boolean and quickly see if there’s a match or not. Let’s continue with more methods: const arr = Īrray.find is also another method we can use to check if our Array contains a certain value. This method can take an additional argument which defines the index from where we want to start looking, leave empty if you want to check the whole Array. We can do that in different ways such as: const arr = Īrray.includes is probably the easiest method to remember and it will return us true or false if our Array includes or not the value we passed. Learn Now Check that an Array contains a valueįirst, let’s look at different ways of checking if our Array includes a certain value provided. ![]()
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