Numbers in Java (with 0 prefix and strings)

Numbers in Java

It is important to understand that the Number class is not a tangible class, but an abstract class. Inside it, we have a set of wrapper classes that define its functionality. These wrapper classes include Integer, Byte, Double, Short, Float, and Long. You may notice that these are the same basic data types we discussed earlier, but they are represented as separate classes with uppercase names to conform to the class naming convention.

The compiler automatically converts primitive data types to objects and vice versa as required for a particular function or program scope, and numeric classes are part of the java.lang package.

This process is called autoboxing and unboxing. By grasping the abstract nature of numeric classes and their corresponding wrapper classes, we can gain a deeper understanding of how Java processes information.

In this article, we will discuss how to add 0 prefix in string by breaking down the topic for better understanding.

How to add a prefix to each element in a Java array?

If you want to change any component of the array, consider adding a prefix to each element of the array. Here are some simple ways to help you do just that -

• First create an array with the components you want to change. Give the array a name, such as "strArray", and give each member a variable name, such as "str".

• Create a for loop to iterate through each member of the next array. Connect the desired prefix to the current element in this loop to change it.

• After using the for-each loop to iterate through the array, you should use a print statement to display the updated value of each member.

• If you want to use a for-each loop, use "for (type var: collection)" syntax to define variables, such as "iterate". Then, as you iterate through each element, the updated value of each element is displayed using the print command.

These simple steps will help you quickly and successfully add your preferred prefix to the elements of your array.

algorithm

• Step 1 - Declare the "strArry" string array variable and initialize it with the titles of three animals: "Dog", "Cat" and "Rabbit".

• Step 2 - To iterate over each member of the "strArry" array, create a for loop.

• Step 3 - Concatenate the phrase "To Pet" with the current element in a for loop and then replace the element's value.

• Step 4 - Construct a second for-each loop that iterates over each element in the "strArry" array and prints the latest number of that element.

• Step 5 - When you run your Java application, the updated values ​​of the array elements will be displayed in the console.

grammar

Let us see the syntax for adding prefix to each element in java.

class Main {
   public static void main (String[] args) {
      String[] strArry = {"Dog", "Cat", "Rabbit"};
      for (int i=0 ; i < strArry.length; i++) {
         strArry[i] = "To Pet " + strArry[i];
      }
      for (String str: strArry) {
         System.out.println (str);
      }
   }
}

Integer prefix 0

algorithm

• Step 1 - Write a Java program that first converts a string with leading zeros to an integer.

• Step 2 - Create the string variable "str" ​​and assign it the value "0000000953".

• Step 3 - To convert a string to a number, use the parseInt() method.

• Step 4 - To convert an integer to a string with leading zeros, use the format() function. To ensure that the integer has five digits in this example, the format specifier "d" is used.

• Step 5 - Finally, use the System.out.println() function to print the output string "Output String:" concatenated with the modified value of "str".

Example 1

The following is an example of adding 0 in front of an integer.

package com.tutorialspoint;
public class StringToInt {
   public static void main(String args[]){
      String str="0000000953";
      /* String to int conversion with leading zeroes
      * the %05 format specifier is used to have 5 digits in
      * the number, this ensures the leading zeroes
      */
      str = String.format("%05d", Integer.parseInt(str));
      System.out.println("Output String: "+str);
   }
}

Output

Output String: 00953

Concatenation of strings and integers

In Java, when a string is concatenated with an integer, the integer is first converted to a string and then concatenated.

algorithm

• Step 1 - Write a Java program that first converts a string with leading zeros to an integer.

• Step 2 - Create the string variable "str" ​​and assign it the value "0000000953".

• Step 3 - To convert a string to a number, use the parseInt() method.

• Step 4 - To convert an integer to a string with leading zeros, use the format() function. To ensure that the integer has five digits in this example, the format specifier "d" is used.

• Step 5 - Finally, use the System.out.println() function to print the output string "Output String:" concatenated with the modified value of "str".

Example 2

The code below explains how string concatenation is used with integers.

import java.io.*;
public class tutorials {
   public static void main (String[] args) {
      String s = 5 + 4 + "World" + 7 + 5;
      System.out.print(s);
   }
}

Output

9World75

in conclusion

We have explored various aspects of working with numbers in Java, including the concept of wrapper classes, autoboxing and unboxing, and ways to add prefixes to the elements of arrays or integers. We have seen how to concatenate a string with an integer and how to convert a string to an integer with leading zeros.

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