using an array to create a string

Question

I'm having an issue with some of my code. I'm receiving a date in the dd/mm/yyyy format as a string called dateofQ.

I want the date to be yyyy_mm_dd, I'm using a string.split() into an array, but it wont return the 3rd array called myArr[3]:

String[] myArr = dateofQ.split("\\/");
String dateFormat = String.format("%s_%s_%s",myArr[2],myArr[1],myArr[0]);

It returns myArr[1] and myArr[0], but when I also add myArr[3] I get an issue at runtime:

Exception in thread "main" java.lang.ArrayIndexOutOfBoundsException: 2
    at ReadFile.main(ReadFile.java:34)

I have tried your code and it works for me. Are you sure that the date really has the dd/mm/yyy format? — Pablo
– Pablo, Commented Oct 4, 2012 at 7:29
Uh. Guys. Again, the OP edited this to read myArray[2] instead of myArr[3], but someone else was also editing it and it overwrote his edit. :-\. — Zéychin
– Zéychin, Commented Oct 4, 2012 at 7:46

nneonneo · Accepted Answer · 2012-10-04 07:21:10Z

6

Well, the array only has 3 elements, and myArr[3] is trying to get the fourth element (remember, arrays are zero-indexed).

To get the third element, use myArr[2].

answered Oct 4, 2012 at 7:21

nneonneo

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4 Comments

Zéychin Over a year ago

He edited it to refer to myArr[2] right as you posted this.

Zéychin Over a year ago

Actually, someone else edited it while he was editing it and overwrote his change, so I put it back in.

Amit Deshpande Over a year ago

Array index happens at 2 index so this is not a solution to his problem.

Zéychin Over a year ago

Well, the OP does say myArr[3]. The OP edited this to say myArr[2], but someone was also editing his post at the same time and overwrote his changes. I edited that back in, but it hasn't been accepted as an edit yet.

Zéychin · Accepted Answer · 2012-10-04 07:24:11Z

2

It looks like the length of myArr is at most 2.

Please check to ensure myArr.length is not at least 3.

Inserting

System.out.println(myArr.length);

right after:

String[] myArr = dateofQ.split("\\/");

is an easy way to check this.

answered Oct 4, 2012 at 7:24

Zéychin

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1 Comment

Amit Deshpande Over a year ago

He should check the length Array Index happened at 2 so there are not enough elements in the array.

MadProgrammer · Accepted Answer · 2012-10-04 07:38:11Z

2

I'm probably missing something really obvious, but couldn't you just do something like...

try {
    String dateofQ = "08/03/1972";
    SimpleDateFormat in = new SimpleDateFormat("dd/MM/yyyy");
    SimpleDateFormat out = new SimpleDateFormat("yyyy_MM_dd");

    dateofQ = out.format(in.parse(dateofQ));
    System.out.println(dateofQ);
} catch (ParseException ex) {
    ex.printStackTrace();
}

Which out puts 1972_03_08

answered Oct 4, 2012 at 7:38

MadProgrammer

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1 Comment

Chris Over a year ago

Thanks this did it. I've never heard of SimpleDateFormat before (I am a noob). I did need to add import java.text.SimpleDataFormat and import java.text.ParseException to get it to work. Thanks again

Amit Deshpande · Accepted Answer · 2012-10-04 07:40:36Z

0

ArrayIndexOutOfBoundsException: 2 This error means you have array of size less than 3 elements and you are trying to access third. i.e. you will get error @ myArr[2].

What you should do is you should check length of array first and then access it. If invalid array reject it.

if(myArr.length==3)//Process else you need to reject

A better way could be use way specified in MadPorgrammer's answer.

answered Oct 4, 2012 at 7:40

Amit Deshpande

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