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Thread: Extremely basic -- help with multiple arguments

  1. #1
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    Default Extremely basic -- help with multiple arguments

    Hello all.

    So my first assignment in my computer science class is to write a program that counts the number of vowels. Basically, running
     java main.Assignment1 "This is one argument" "A second one"
    should return
    Argument 1: 1 a, 2 e, 2 i, 1 o, 1 u
    Argument 2: 1 a, 2 e, 0 i, 2 o, 0 u
    All: 2 a, 4 e, 2 i, 3 o, 1 u
    .

    I'm very new Java. I have a working code, but it would only work for one argument:

    package main;
    public class Assignment1 {
     
    	public static void main(String args[]) {
    		String str = args[0];
     
    		int numA = 0;
    		int numE = 0;
    		int numI = 0;
    		int numO = 0;
    		int numU = 0;
     
    		for (int i = 0; i < str.length(); i++) {
    			char c = str.charAt(i);
    			if (c == 'A' || c == 'a') {
    				numA++;
    			}
    			if (c == 'E' || c == 'e') {
    				numE++;
    			}
    			if (c == 'I' || c == 'i') {
    				numI++;
    			}
    			if (c == 'O' || c == 'o') {
    				numO++;
    			}
    			if (c == 'U' || c == 'u') {
    				numU++;
    			}
    		}
    		System.out.print("Argument 1: ");
    		System.out.print(numA + " a, ");
    		System.out.print(numE + " e, ");
    		System.out.print(numI + " i, ");
    		System.out.print(numO + " o, ");
    		System.out.print(numU + " u");
    	}
    }

    My question is how can I make this work for any number of input arguments?


  2. #2
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    Default Re: Extremely basic -- help with multiple arguments

    Could follow the approach you've already been following, but enclose all of it in a for loop. You could then do String str = args[indexOfEnclosingLoop];.
    Please use [highlight=Java]//code goes here...[/highlight] tags when posting your code

  3. #3
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    Default Re: Extremely basic -- help with multiple arguments

    Do what you are currently doing for each element of the args[] array.

    Stop and think first. Describe what you will do in real life language before you attempt it in code. Your description will probably begin "For each string in the args[] array...".

    Then attempt what you have come up with in code. It depends on what steps you intend taking, but my guess is that your description of the process will involve a second for loop and some more variables.

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    Default Re: Extremely basic -- help with multiple arguments

    Quote Originally Posted by newbie View Post
    Could follow the approach you've already been following, but enclose all of it in a for loop. You could then do String str = args[indexOfEnclosingLoop];.
    I was thinking something like this, but how can the program know to use all of the arguments (be it 2 or 5000)?

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    Default Re: Extremely basic -- help with multiple arguments

    Quote Originally Posted by jhnhskll View Post
    I was thinking something like this, but how can the program know to use all of the arguments (be it 2 or 5000)?
    Arrays have a length property, discussed in the Arrays page of Oracle's Tutorial.

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    Default Re: Extremely basic -- help with multiple arguments

    Thanks for the help guys! Here's what I'm working with now:

    package main;
     
    public class Assignment1 {
     
    	public static void main(String args[]) {
    		int numA = 0;
    		int numE = 0;
    		int numI = 0;
    		int numO = 0;
    		int numU = 0;
     
    		for (int idx = 0; idx <= (args.length - 1); idx++) {
    			String str = args[idx];
     
    			for (int i = 0; i < str.length(); i++) {
    				char c = str.charAt(i);
    				if (c == 'A' || c == 'a') {
    					numA++;
    				}
    				if (c == 'E' || c == 'e') {
    					numE++;
    				}
    				if (c == 'I' || c == 'i') {
    					numI++;
    				}
    				if (c == 'O' || c == 'o') {
    					numO++;
    				}
    				if (c == 'U' || c == 'u') {
    					numU++;
    				}
    			}
     
    			System.out.print("Argument " + (idx + 1) + ": ");
    			System.out.print(numA + " a, ");
    			System.out.print(numE + " e, ");
    			System.out.print(numI + " i, ");
    			System.out.print(numO + " o, ");
    			System.out.println(numU + " u");
    		}
    		System.out.print("All: ");
    		System.out.print(numA + " a, ");
    		System.out.print(numE + " e, ");
    		System.out.print(numI + " i, ");
    		System.out.print(numO + " o, ");
    		System.out.println(numU + " u");
    	}
    	}
    }

    This returns
    Argument 1: 1 a, 2 e, 2 i, 1 o, 1 u
    Argument 2: 2 a, 4 e, 2 i, 3 o, 1 u
    All: 2 a, 4 e, 2 i, 3 o, 1 u
    when run with the arguments "This is a string" and "Another one"

    Now the only issue I'm having is figuring out how to count each separate argument instead of just increasing the count for all of them. I have no idea how to approach this =/

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    Default Re: Extremely basic -- help with multiple arguments

    Glad you solved it, and thanks for sharing your solution jhnhskll.
    Please use [highlight=Java]//code goes here...[/highlight] tags when posting your code

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    Default Re: Extremely basic -- help with multiple arguments

    Quote Originally Posted by newbie View Post
    Glad you solved it, and thanks for sharing your solution jhnhskll.
    Well, I haven't quite gotten it yet. I need some way to count the vowels in each argument separately.

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    Default Re: Extremely basic -- help with multiple arguments

    Apologies yes, I was away with the fairies when I read your post.
    A basic way to accomplish what you need is to use more variables, which you also print, then add to final tally, before resetting the new variables back to 0 at the end of each iteration.
    Please use [highlight=Java]//code goes here...[/highlight] tags when posting your code

  10. #10
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    Default Re: Extremely basic -- help with multiple arguments

    Quote Originally Posted by newbie View Post
    Apologies yes, I was away with the fairies when I read your post.
    A basic way to accomplish what you need is to use more variables, which you also print, then add to final tally, before resetting the new variables back to 0 at the end of each iteration.
    Ohhh I totally get it now. Code working as intended! Thanks for the help!

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