JAVA SCANNER TUTORIAL AND CODE EXAMPLES
Basically, the scanner class is used to read all the data which have been collected. Java scanner is built into the Java until package so that in future any time the external librarian can read them. The scanner will read-only if the text is from standard input, or else it will not read the text if those not from the standard input.
It is really very important to know how to get user input in Java.This text will is required to return back to the main program so that the data can be store without having any kind of leakage of data, or else it may get manipulated by any wrong hands. In further, we will discuss how to utilize the java scanner to receive user input.
NEED OF JAVA SCANNER CLASS
We can collect the user input by using the scanner class. The scanner class will read text only if the user inserts it into the console and sends all those texts back to a program.Java scanner is the one and only primary method of collecting java user input.
There is no doubt that we can create a variable which is called input which collects the next value which the user inputs into the console. After this, we can easily create a variable that is called a number that collects the value which has been submitted by the console. We are required to know each and every type of essential methods to proceed further.
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SCANNER PROGRAM THE WAY OF IT WORKS
Now we are going to learn how does the Java scanner works, and we will get to know in this;
1) Usually, we import the scanner library into our code so that it will be easy for us to receive user input.
2) The code which stores the code of our program, which we declare a class, is called Computer Inventory.
3) Usually, we initialize the scanner class by using the scanner input= new scanner(system. in). Basically, the input Java variable stores all our initialized scanner.
4) Usually, we print out those product name to the console, and after that, we ask the user to submit a product name by user input. next().
5) We usually print out to the console only those product name which the user submitted.
6) Here, we basically print out Quantity; the console encourages the user to promote to submit the quantity of the product.
7) We offer a print of all the value of the quantity variable to the console.
SCANNER DIFFERENT INPUT TYPE
As far as now, we have collected two different types of data from the user.
One data name is a string, and another data name is an integer. To collect this type of data from the user, we are required to type different codes. Both these data string and an integer are obtained by separate methods.
The methods which are used here are;
nextBoolean(), nextBye(),nextDouble(),nextFloat(), nextLine(), nextLong(), nextShort().
The different types of value the method collects are;
Boolean, byte, double, float, int, string, long, short.
If we insert any kind of wrong input type, it may result where our program will raise an Input Mismatch Exception.
For example; If we try to insert any type of a double into a field that usually collects Booleans, it may happen that the program will raise an exception in that.
VALUE THAT HAS DEPICTED FROM BOOLEAN
Now, let us go back to the computer store where all the data are saved and have strong security. It is that method where we can read our saves input scanner whenever we want to have a crosscheck of it.
Like it has often happened that if the wanted to update our first program, we always allow our computer store manage to input whether the products are displayed properly on the screen or held in between of the stockroom of the methods.
The time when we have collected an additional value from the user where the produces they have inserted into the program is properly displayed on-screen or not.
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It has always been seen that Scanner class has always been a capable program of collecting various data type from the users.
Here we have got to know about how to use the Java Scanner class to collect user input.