array functions javascript code example

Example 1: javascript array functions

concat(arr1,[...]) // Joins two or more arrays, and returns a copy of the joined arrays
copyWithin(target,[start],[end]) // Copies array elements within the array, to and from specified positions
entries() // Returns a key/value pair Array Iteration Object
every(function(currentval,[index],[arr]),[thisVal]) // Checks if every element in an array pass a test
fill(val,[start],[end]) // Fill the elements in an array with a static value
filter(function(currentval,[index],[arr]),[thisVal]) //	Creates a new array with every element in an array that pass a test
find(function(currentval,[index],[arr]),[thisVal]) // Returns the value of the first element in an array that pass a test
findIndex(function(currentval,[index],[arr]),[thisVal]) // Returns the index of the first element in an array that pass a test
forEach(function(currentval,[index],[arr]),[thisVal]) // Calls a function for each array element
from(obj,[mapFunc],[thisVal]) // Creates an array from an object
includes(element,[start]) // Check if an array contains the specified element
indexOf(element,[start]) // Search the array for an element and returns its position
isArray(obj) // Checks whether an object is an array
join([seperator]) // Joins all elements of an array into a string
keys() // Returns a Array Iteration Object, containing the keys of the original array
lastIndexOf(element,[start]) // Search the array for an element, starting at the end, and returns its position
map(function(currentval,[index],[arr]),[thisVal]) // Creates a new array with the result of calling a function for each array element
pop() // Removes the last element of an array, and returns that element
push(item1,[...]) // Adds new elements to the end of an array, and returns the new length
reduce(function(total,currentval,[index],[arr]),[initVal]) // Reduce the values of an array to a single value (going left-to-right)
reduceRight(function(total,currentval,[index],[arr]),[initVal]) // Reduce the values of an array to a single value (going right-to-left)
reverse() // Reverses the order of the elements in an array
shift() // Removes the first element of an array, and returns that element
slice([start],[end]) // Selects a part of an array, and returns the new array
some(function(currentval,[index],[arr]),[thisVal]) // Checks if any of the elements in an array pass a test
sort([compareFunc]) // Sorts the elements of an array
splice(index,[quantity],[item1,...]) // Adds/Removes elements from an array
toString() // Converts an array to a string, and returns the result
unshift(item1,...) // Adds new elements to the beginning of an array, and returns the new length
valueOf() // Returns the primitive value of an array

Example 2: js array

var colors = [ "red", "orange", "yellow", "green", "blue" ]; //Array

console.log(colors); //Should give the whole array
console.log(colors[0]); //should say "red"
console.log(colors[1]); //should say "orange"
console.log(colors[4]); //should say "blue"

colors[4] = "dark blue" //changes "blue" value to "dark blue"
console.log(colors[4]); //should say "dark blue"
//I hope this helped :)

Example 3: javascript array methods

// ... : Variadic (As many args as memory can handle) 
// [arg] : Optional Argument

concat(arr1,[...]) // Joins two or more arrays, and returns a copy of the joined arrays
copyWithin(target,[start],[end]) // Copies array elements within the array, to and from specified positions
entries() // Returns a key/value pair Array Iteration Object
every(function(currentval,[index],[arr]),[thisVal]) // Checks if every element in an array pass a test
fill(val,[start],[end]) // Fill the elements in an array with a static value
filter(function(currentval,[index],[arr]),[thisVal]) //	Creates a new array with every element in an array that pass a test
find(function(currentval,[index],[arr]),[thisVal]) // Returns the value of the first element in an array that pass a test
findIndex(function(currentval,[index],[arr]),[thisVal]) // Returns the index of the first element in an array that pass a test
forEach(function(currentval,[index],[arr]),[thisVal]) // Calls a function for each array element
from(obj,[mapFunc],[thisVal]) // Creates an array from an object
includes(element,[start]) // Check if an array contains the specified element
indexOf(element,[start]) // Search the array for an element and returns its position
isArray(obj) // Checks whether an object is an array
join([seperator]) // Joins all elements of an array into a string
keys() // Returns a Array Iteration Object, containing the keys of the original array
lastIndexOf(element,[start]) // Search the array for an element, starting at the end, and returns its position
map(function(currentval,[index],[arr]),[thisVal]) // Creates a new array with the result of calling a function for each array element
pop() // Removes the last element of an array, and returns that element
push(item1,[...]) // Adds new elements to the end of an array, and returns the new length
reduce(function(total,currentval,[index],[arr]),[initVal]) // Reduce the values of an array to a single value (going left-to-right)
reduceRight(function(total,currentval,[index],[arr]),[initVal]) // Reduce the values of an array to a single value (going right-to-left)
reverse() // Reverses the order of the elements in an array
shift() // Removes the first element of an array, and returns that element
slice([start],[end]) // Selects a part of an array, and returns the new array
some(function(currentval,[index],[arr]),[thisVal]) // Checks if any of the elements in an array pass a test
sort([compareFunc]) // Sorts the elements of an array
splice(index,[quantity],[item1,...]) // Adds/Removes elements from an array
toString() // Converts an array to a string, and returns the result
unshift(item1,...) // Adds new elements to the beginning of an array, and returns the new length
valueOf() // Returns the primitive value of an array

Example 4: javascript array methods

let fruits = ['Apple', 'Banana']

console.log(fruits.length)
// 2

Example 5: array methods in javascript

<script>    
    // Defining function to get unique values from an array
    function getUnique(array){
        var uniqueArray = [];
        
        // Loop through array values
        for(var value of array){
            if(uniqueArray.indexOf(value) === -1){
                uniqueArray.push(value);
            }
        }
        return uniqueArray;
    }
    
    var names = ["John", "Peter", "Clark", "Harry", "John", "Alice"];
    var uniqueNames = getUnique(names);
    console.log(uniqueNames); // Prints: ["John", "Peter", "Clark", "Harry", "Alice"]
</script>

Example 6: functions in arrays javascript

var argsContainer = ['hello', 'you', 'there'];
var functionsContainer = [];

for (var i = 0; i < argsContainer.length; i++) {
var currentArg = argsContainer[i]; 

  functionsContainer.push(function(currentArg){
    console.log(currentArg);
  });
};

for (var i = 0; i < functionsContainer.length; i++) {
  functionsContainer[i](argsContainer[i]);
}

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