Skip to main content

Introduction to Primitives - Java

2. Overview:

There are eight primitive data types byte, short, int, long, float, double boolean, char. These eight data types store values as raw instead of Objects these primitives help to save memory to a great extent and simplify other processes as they are directly stored in the stack.

Data Type Size(in bits) Minimum Range Maximum Range
byte 8 -128 127
short 16 -32768 32767
int 32 -2147483648 2147483647
long 64 -9223372036854775808 9223372036854775807
float 32 -3.4e38 to -1.4e-45 1.4e-45 to 3.4e38
double 64 -1.8e308 to -4.9e-324 4.9e-324 to 1.8e308
boolean 1 - -
char 16 space 65535

  1. byte

    A byte has the capacity of 8 bits or 1 byte and it can store numbers between -27 and 27 -1 or simply -128 to 127.
    This is very useful while dealing with large arrays as they are way better than int or short arrays while considering memory efficiency and if the value is in the said range.
    The default value is 0

    byte number = 125;
    byte num;

  2. short

    A short is if you want to save memory but byte is too small for your activity and int is too large then the short data type is for there for your rescue which has a memory space of 16 bits or 2 bytes which can store the numbers between -2 15 and 215-1 or simply -32,768 to 32,768.
    The default value is 0.

    short number = 125;
    short num;

  3. int

    An int is the go-to data type for a number by the programmers as they need not worry about the range for their basic calculation for everyday problem solving, the size is 32 bits or 4 bytes and has a range of -231 and 231-1 or in simple numbers -2,147,483,648 to 2,147,483,647.
    The default value is 0

    int number = 599999;
    int num;

  4. float

    A float is a data type that can store decimals but can guarantee the precision only until the decimal place is 6 or less otherwise the value becomes an estimate but the size is the same as int which is 32 bits or 4 bytes but the range is 1.40239846 x 10-45, and the largest value is 3.40282347 x 1038.
    The defalut Value is 0.0f
    float values must end with litrial f

    float number = 3.14129f;
    float num;

  5. double

    A double is also a data type that can store decimals, but the name suggests the size is double of the float, which is 64 bits or 8 bytes and the range is 4.9406564584124654 x 10-324 to 1.7976931348623157 x 10308
    The defalut Value is 0.0d
    double values must end with litrial d

    double number = 3.14129d;
    double num;

  6. boolean

    A boolean can store only 2 values true and false which are primarily used for the control of the loops or other methods the size is just 1 bit but java stores it as 1 byte.
    The default value is false

    boolean run = true;
    double num;

  7. char

    The last data type is char which is a 16-bit integer representing a Unicode-encoded character. Its range is from 0 to 65,535 which in Unicode represents ‘\u0000' to ‘\uffff'.
    The default value is (single space) or empty character

    char c = 'H';
    char s;

Some Important points

  • The default value is applicable only for instance variables or simply variables declared inside the class but outside the constructor.
  • String: Even though the string is declared and acts like a primitive in java it is basically a class every time we create a string an object is created with a sequence of characters in a char array.
  • Using underscore between two numbers are legal in java example int k = 59_6565_231; just not the begining or end of the numbers and in case of decimals not next to them either..
Labels:

Comments

Post a Comment

Popular posts from this blog

Linked List in Java - Collections Framework- DSA

Gist: A Linked list is dynamic array where a group of object can be stored while following the insertion order and allow duplicates, the 2 type of linked list is singly and double linked lists, the default one is single linked list where the elements can be traversed only in forward direction this is because unlike array here the elements are stored at random locations and only the node of each element knows the address of the next element. A simple example would be our circut board here a point X may be connection to Y and Y connectioned to pont Z here the insertion order is preserved and we can know the next point only by following the signals from the previous point. Same as the example but in Linked list each element has 2 parts in singly linked list where 1 part is the node with the adress to the next node and the other which is the actua data of that element like a post letter the envelop has the address and inside the contents. but in doubly linked list there are 3 parts ...
Post a Comment
Read more

Designer PDF Viewer - HackerRank Problems

Difficulty: EASY Problem : The objective here is to find the size of the highlighted area, and we are given the size's of all the alphabets, we have to find the largest alphabet in the highlighted word and then calculate the size of the rectangle so if the tallest character is 3 then the size of the box will be 3 * number of characters given. Visual representation of the selection : abc def ghij Inputs An array with the sizes of all alphabets a-z in order. A String of highlighted words. Important points to note The array which holds the height of each character in ascending order which means the arrays 0th index will have the height of a 1st index will have the height of b and so on and so forth in the end the hight of z will be there so it's easy to locate each character. A String with the highlighted word. This means we have got the characters inside the rectangle, all we have to find is ...
Post a Comment
Read more

Naming Conventions in Java

Naming Conventions in Java As the movies are rated G, PG, U, A depending on the age restriction and by just gazing through the rating our parents decide the movie to watch together, or a book with diffrent labels to keep track of the sections and just by seeing them we know what they represent, the same labeling method has been introduced by Java team to diffrenciate variables, methods, classes, constants etc.. and we will be going through them all here. Type Naming Convention Example Variables Must start with a lower case and every other word capitalized int counter; Constants Must all be upper case and _ for diffrenciating every other word final int MAX_HEALTH = 100; Methods Must start with a lower case and every other word capitalized. can be distingiused from the variable by the () next to the method name void printNum(){..} Class Must start an upper case letter and every other word must ...
Post a Comment
Read more