Should findByCriteria method return true if searching empty string for criteria[n]

[pkinuk Buler]

Hi all,

The following is the findByCriteria method in the DBAccess interface.

   
/**
     * Returns an array of record numbers that match the specified criteria.
     * Field n in the database file is described by criteria[n]. A null value in
     * criteria[n] matches any field value. A non-null value in criteria[n]
     * matches any field value that begins with criteria[n]. (For example,
     * "Fred" matches "Fred" or "Freddy"
     */
    public long[] findByCriteria(String[] criteria);
 

I use the String.startsWith method to judge the condition:

A non-null value in criteria[n] matches any field value that begins with criteria[n]. (For example, "Fred" matches "Fred" or "Freddy"

.

But I found that if the criteria[n] is an empty string, the String.startsWith returns ture.

for example:

    
String s1 = "test";
String s2 = "";

// The following condition will be ture:
s1.startWith(s2);

My question is if the parameter criteria is array like

 String[] aa = { "", "", "", "", "", "" };   

, should it return the matched record?

[Roberto Perillo]

Hey, Pkinuk!

My question is if the parameter criteria is array like

 String[] aa = { "", "", "", "", "", "" };   

, should it return the matched record?

Well, interesting thing you found out. I myself didn't make such verification. Here's what I did:

if (criteria[i] != null && record[i].toLowerCase().startsWith(criteria[i].toLowerCase())) {...}

So I just verify if it isn't null. In my implementation, this record would be returned.

[Andy Jung]

Hi Robert,

by applying the String method toLowerCase() you realize matching in a case-insensitive style.

Is this a requrement or do you just go fine having just a case-sensitive match without using methods like toUpperCase / toLowerCase?

Regards,
Andy

[Roel De Nijs]

Hi all,

I have similar code as Roberto.

@Andy: I used the toLowerCase function too. It's not a must requirement, so you don't have to do it at all. But I'd just decided to implement case insensitive searching in my Data class. That's all

Kind regards,
Roel

[pkinuk Buler]

Hi all,
I also use similar code as Roberto to match the criteria. Since you all can pass the exam by using same theory to implement the findByCriteria method, I don't think I will fail.

Thank you all.