PHP Companies Interview Questions and Answers for Experienced

Weak reference is a reference that does not prevent the object from being garbage collected.

• Weak references are used to refer to objects that can be garbage collected if there are no strong references to them.

• They are typically used in scenarios where you want to hold a reference to an object, but don't want to prevent it from being collected.

• Weak references are implemented using weak reference queues, which allow you ...read more

Singleton pattern ensures a class has only one instance, while allowing global access to it.

• Implement a private constructor to prevent direct instantiation.

• Create a static method to provide a single point of access to the instance.

• Use lazy initialization to create the instance only when needed.

• Ensure thread safety in a multithreaded environment using synchronization or double-checked locking.

• Breaking the singleton patt...read more

Annotations used in Spring Framework for defining components and services.

• Annotations like @Component, @Service, and @Controller are used for defining components in Spring Framework.

• @RestController is used for defining RESTful web services.

• @Configuration is used for defining configuration classes.

• @Transactional is used for defining transactional methods.

• All these annotations help in defining and managing dependencies i

HashSet is implemented using a HashMap internally. Same hashcode is generated when two objects have the same value for hashCode() and equals() methods.

• HashSet internally uses a HashMap to store its elements.

• The hashcode of an object is generated using the hashCode() method.

• If two objects have the same value for hashCode() and equals() methods, they will generate the same hashcode.

• For example, if two String objects have...read more

SQL Cursor is a database object used to manipulate data row by row.

• Cursor is used to fetch and process data row by row

• Index is a database object used to speed up data retrieval

• Aggregate functions are used to perform calculations on a set of values

• Examples of aggregate functions are SUM, AVG, COUNT, MAX, MIN

Generate palindrome string with given length and distinct characters.

• Create a char array of length n and fill it with distinct characters.

• Loop through the array and add the characters in reverse order to create a palindrome.

• Repeat the process until the required number of palindromes are generated.

• If k is less than the length of the palindrome, use the first k distinct characters.

Find the highest value that occurs the same number of times within an array.

• Iterate through the array and count the occurrences of each value.

• Store the counts in a dictionary or hash map.

• Find the maximum count and check which value(s) have that count.

• Return the highest value among those with the maximum count.

Count occurrences of a character in a string and output in a specific format.

• Use a hash table to store the count of each character.

• Loop through the string and update the count in the hash table.

• Create the output string using the hash table.

Converts a string from Camel case to Snake case.

• Loop through the string and check for uppercase letters

• Insert an underscore before each uppercase letter

• Convert the string to lowercase

Logic to get Map using Stream API to show balance of each person

• Use Stream API to group accounts by name

• Use map() to get the sum of balances for each group

• Collect the results into a Map

Financial instruments are tradable assets that represent a legal agreement between two parties to buy or sell an asset at a predetermined price and time.

• Financial instruments include stocks, bonds, options, futures, and derivatives.

• Asset classes are groups of financial instruments that share similar characteristics and behave similarly in the market.

• Examples of asset classes include equities, fixed income, commodities,...read more

The primary market is where new securities are issued and sold for the first time.

• It is the market where companies raise capital by issuing new stocks or bonds.

• Investors can purchase these securities directly from the issuing company.

• Examples include initial public offerings (IPOs) and corporate bond offerings.

The secondary market refers to the financial market where previously issued securities are bought and sold.

• It is a market where investors can trade securities that have already been issued.

• It provides liquidity to investors by allowing them to buy and sell securities after their initial issuance.

• The secondary market includes stock exchanges, bond markets, and other platforms where securities are traded.

• Investors can bu...read more

Futures and options are financial derivatives that allow investors to speculate on the future price movements of an underlying asset.

• Futures contracts are agreements to buy or sell an asset at a predetermined price on a specified future date.

• Options contracts give the holder the right, but not the obligation, to buy or sell an asset at a predetermined price within a specified period.

• Both futures and options are commonl...read more

The derivative is a mathematical concept that represents the rate of change of a function at a particular point.

• The derivative measures how a function changes as its input changes

• It is defined as the slope of the tangent line to the graph of the function at a given point

• The derivative can be used to find the maximum and minimum values of a function

• It is commonly used in calculus to solve problems involving rates of cha...read more

There are several types of trade, including international trade, domestic trade, wholesale trade, and retail trade.

• International trade involves the exchange of goods and services between countries.

• Domestic trade refers to the buying and selling of goods and services within a country.

• Wholesale trade involves the sale of goods in large quantities to retailers or other businesses.

• Retail trade involves the sale of goods to...read more

Capital market deals with long-term securities while money market deals with short-term securities.

• Capital market is a market for long-term securities such as stocks, bonds, and debentures.

• Money market is a market for short-term securities such as treasury bills, commercial papers, and certificates of deposit.

• Capital market is used for raising long-term funds for investment in fixed assets.

• Money market is used for shor...read more

Changes in share purchasing and selling

• Introduction of online trading platforms

• Implementation of circuit breakers to prevent extreme price fluctuations

• Introduction of transaction taxes in some countries

• Increased use of algorithmic trading

• Regulatory changes to increase transparency and prevent insider trading

Calculation of brokerage is based on the percentage of the transaction value.

• Brokerage is calculated as a percentage of the transaction value

• The percentage may vary depending on the type of security being traded

• For example, the brokerage for equity shares may be different from that of mutual funds

• Brokerage may also be subject to a minimum and maximum limit

• The brokerage amount is deducted from the investor's account

• The ...read more

IPO stands for Initial Public Offering. It is the process by which a private company becomes a publicly-traded company by offering its shares to the public.

• IPO is a way for companies to raise capital by selling shares to the public.

• It allows private companies to become publicly traded on stock exchanges.

• During an IPO, shares are offered to institutional investors and individual investors.

• The company's valuation and sha...read more

Bonds are debt securities that are issued by companies, governments, and other organizations to raise capital.

• Government bonds: Issued by governments to finance their operations

• Corporate bonds: Issued by companies to finance their operations

• Municipal bonds: Issued by local governments to finance public projects

• Treasury bonds: Issued by the US government to finance its operations

• Junk bonds: High-risk, high-yield bonds i

Capital markets are where financial instruments such as stocks, bonds, and commodities are traded between investors and institutions.

• Capital markets are a platform for companies to raise capital by issuing stocks and bonds.

• Investors can buy and sell financial instruments in the capital markets.

• The capital markets are divided into primary and secondary markets.

• Examples of capital markets include the New York Stock Excha...read more

Short term liabilities are debts or obligations that are due within a year or less.

• Short term loans

• Accounts payable

• Accrued expenses

• Current portion of long-term debt

• Unearned revenue