The use of "if" statements

[agnl666]

I'm completely new to programming and don't have a complete understanding of the syntax of java though I am slowly grasping it. I was wondering how if, else, and else if statements need to be written and formatted in java ? If people could post some simple code to demonstrate as well. Also how to get input in java?

Thanks

[Generic]

    public static void main(String[] args) { // Our code starts here.
        int i = 0; // Declare variable "i" as 0.
        if (i == 0) { // if "i" is equal to 0
            
        } else if (i == 1) { // if "i" is equal to 1
            
        } else { // if none of the other conditions are met
            
        }
    }

is equivalent to

    public static void main(String[] args) { // Our code starts here.
        int i = 0; // Declare variable "i" as 0.
        
        if (i == 0) { // if "i" is equal to 0
        } else {
            if (i == 1) { // if "i" is equal to 1
                
            } else { // if none of the other conditions are met
                
            }
        }
    }

The first being far more legible making else if statements more advantageous.

[Orjan]

input through command line programs is with for example the java.util.Scanner class, instanciated with System.in as parameter

java.util.Scanner scn = new java.util.Scanner(System.in);
String myStringVar = scn.nextLine();

[agnl666]

Cool. Thanks. I figured the if statements out but I'm still working on getting the hang of the input statements. Thank you

[sourlemon]

There are two ways (that I use) to read input with Scanner, by reading one word at a time or one line at a time. The Scanner object help you do this.

When you want to read an input, you first "declare" so:

java.util.Scanner scan = new java.util.Scanner(System.in);

To read a line you use: scan.nextLine() which will return a string. A line is indicated by the character '\n' (aka the enter key).

String line = scan.nextLine();

If you want to read a word, then you use scan.next() which will also return a string. Word can be separated by a space or new line character.

String word = scan.next();

To read more than one word or more than one line, just repeat the code. Example:

String word1 = scan.next();
String word2 = scan.next();
String word3 = scan.next();

Same with line. Hopefully that explained it a bit more. Good luck!

[agnl666]

Ya, thanks. If I wanted to read an int as opposed to a string would I simply put "scan.nextInt();" ?

[Orjan]

that's true. but, to make sure it's an int coming, you should check it with "scan.hasNextInt();" which returns a boolean if there is an in int scanned.

[G1TN3RD]

Ima just do both, even though you have one already.

int number = 0;
if(number==0)
{
    System.out.println("The number is equal to zero");
{
else
{
    System.out.println("The number is not equal to zero");
}

And the input is depressed to the to .in
For ex. if you are reading a text file, and you need to capture some data from the text file and make it input for java...

import java.util.Scanner;
import java.io.*;

public class insertnamehere
{
    public static void main (String[] args) throws IOException
    {
        Scanner in = new Scanner (new File("whatever your file name is here"));
       in.NextLine();         <------ whatever was on the first line of that data file, has now been saved as data in java...

Or you can declare something with the input statement

String line = in.nextLine();

hope that helps =)