Programming Articles - Page 1121 of 3366

The forEach() method in Node.js is used for iterating over a set of given array items. One can iterate over all the values of the array one-by-one using the forEach array loop.SyntaxarrayName.forEach(function)Parametersfunction − The function takes input for the method that will be executed.arrayName − Array that will be iterated.Example 1Create a file "forEach.js" and copy the following code snippet. After creating the file, use the command "node forEach.js" to run this code. Live Demo// forEach() Demo Example // Defining a vehicle array const vehicleArray = ['bike', 'car', 'bus']; // Iterating over the array and printing vehicleArray.forEach(element => {    console.log(element); ... Read More

The Hmac class is one of the many utility classes that is used for creating the cryptographic HMAC digests. The Hmac.update() method is used for updating the Hmac content with the data passed. If encoding is not provided and the data is in string format, then the default encoding 'utf8' is enforced.Syntaxhmac.update(data, [encoding])ParametersThe parameters are described below:data − This input parameter takes input for the data with which Hmac will be updated.encoding − This input parameter takes input for the encoding to be considered while updating the Hmac.Example 1Create a file with the name "hmacUpdate.js" and copy the following code snippet. After ... Read More

The util.deprecate() method wraps fn (that may be a function or class) in such a way that it is marketed as a deprecated method. The util.deprecate() method returns a function that emits a DeprecationWarning. This warning is printed to the stderr when the function is called the first time. The function is called without any warning once the warning is emitted.Syntaxutil.deprecate( fn, msg, [code] )ParametersThe parameters are defined below:fn − The function that needs to be deprecated.msg − This is a warning message which is invoked once the deprecated function is called.code − This is an optional parameter which displays the passed ... Read More

The util.types.isBoxedPrimitive() method checks whether the passed value is a built-in Primitive object or not. If the above condition is satisfied, it returns True, else False. Primitive object includes new Boolean(), new String() or Object(Symbol()).Syntaxutil.types.isBoxedPrimitive(value)Parametersvalue − This input value takes input for the required parameter and checks if it's a Float32-Array instance or not.It returns True or False based upon the input value passed.Example 1Create a file with the name "isBoxedPrimitive.js" and copy the following code snippet. After creating the file, use the command "node isBoxedPrimitive.js" to run this code.// util.types.isBoxedPrimitive() Demo Example // Importing the util module const util ... Read More

HasPathsum takes 2 parameters one is the tree node and other is the sum value, initially we check whether the node is null or not, if the node is null then we return false. If the node is not null then we call HasPathSum recursive method, in each and every recursive step we keep on subtracting the sum value from the node value. If the value of the sum reaches 0 then we come to conclusion that the given tree has the path that is equal to sum and return true.Examplepublic class TreesPgm{    public class Node{       ... Read More

A tree is a binary search tree if it has all the left child lesser than the node elements and all the right child greater than the node elements. Initially we check whether the node has any value, if the node is null then we consider as valid binary search tree and return true. After checking the node null result, we call the recursive method isValidBST by passing the node, min value and max value. If the root value is lesser than min and the root value is greater than max we consider as not a binary search tree and ... Read More

To invert a binary search tree, we call a method InvertABinarySearchTree which takes node as a parameter. If the node is null then return null, if the node is not null, we call the InvertABinarySearchTree recursively by passing the left and right child values. and assign the right child value to the left child and left child value to the right child. The final output will consist of the tree which will be its own mirror image.Examplepublic class TreesPgm{    public class Node{       public int Value;       public Node LeftChild;       public Node ... Read More

In the recursive approach we to find a tree is symmetric or not we initially check whether the tree is null or not, if the tree is null then its symmetric, if the tree is not not null we call amethod issymmetricmirror .In isSymmetricMirror we get the value of the left child and right child, if both left and right child are null we consider as symmetric, if either of the value is null then we consider and not symmetric and at last we call the issymmetric method recursively by passing the left and right child values.Examplepublic class TreesPgm{   ... Read More

In the Iterative approach we have to create 2 Queues, one queue saves the left child and another queue saves the right child value. If the tree is empty, then it is symmetrical to the vertical axis going through its root node. Else, check if the value at the root node of both subtrees is the same. If it is, then check if the left subtree and the right subtree are symmetrical. Enqueue the left child value and right child value into the queue1 and enqueue the right child and left child value into the queue1Examplepublic class TreesPgm{    public ... Read More

CoinChangeBottomUpApproach takes 3 parameters as input n is the amount, coins array contains the total number of coins, t contains total number of coins. Declare a dynamic array which stores the previously calculated values. loop through the array and calculate the minimum coins required to calculate the amount. If the calculation is already done the take the value from the dynamic array.Time complexity − O(N)Space complexity − O(N)Examplepublic class DynamicProgramming{    public int CoinChangeBottomUpApproach(int n, int[] coins, int t){       int[] dp = new int[100];       for (int i = 1; i < n; i++){   ... Read More