CODEWITHSUNDEEP
java
user4192725
user4192725

Reputation: 25

Count the length of an array

I having an input file
First line is the size of array(N) Second line is N element

I have to proceeded if N ==No of element in second line For EX:

3
1 3 4 //ok
4
3 5 6 7 7 // Do nothing

My code:

Scanner in = new Scanner(new FileReader("ok.txt"));
int n = in.nextInt();
if(n==in.nextLine().length())
// MAke an array of element


in.nextLine().length() Is not giving me a correct length i.e 3 and 5

Upvotes: 0

Views: 116

Answers (4)

Spikatrix
Spikatrix

Reputation: 20244

int n = in.nextInt();
if((n*2)==(in.nextLine().length()-1))
//correct length
else
//Incorrect length

Try the above code. In the file,if integers are seperated by spaces,then it also counts as a character in length. Subtracting one from length is because the number of spaces is one less than the number of integers. Note that the above is applicable only when n>1.

Upvotes: 0

msrd0
msrd0

Reputation: 8361

You could use this code to read two lines. The method will return null if the size doesn't match, and the array otherwise.

public String[] readTwoLines (BufferedReader in)
{
    int length = Integer.parseInt(in.readLine());
    String[] ints = in.readLine().split("\\s+");
    if (ints.length == length) return ints;
    return null;
}

Upvotes: 0

yunandtidus
yunandtidus

Reputation: 4086

in.nextLine() will give you a String containing :

"1 3 4"

with 2 spaces and 3 digits. You should do : 

String line = in.nextLine();
String[] digits = line.split(" ");
if (n==digits.length) {
    ...

Moreover be aware of the fact that using in.nextLine() in your if condition, leads you to lost the content of the line

Upvotes: 5

Bob Ezuba
Bob Ezuba

Reputation: 510

I hope this helps with your question, assuming that I understood your question.

    BufferedReader reader = null;
    try{
        reader = new BufferedReader(new FileReader("yourFile.txt"));
        int array_size = Integer.parseInt(reader.readLine());
        String[] array = reader.readLine().split("\\s+");
        if(array_size == array.length){
            //continue
        }
    }catch(Exception ex){
        ex.printStackTrace();
    }

Upvotes: 0

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