CODEWITHSUNDEEP
java
user3059511
user3059511

Reputation:

extract a smaller number from a larger number

I am in a situation where I want to take a long UPC //12 digits and extract digits 1-6 and store them as private final MANUFACTURER_ID and also digits 7-11 to store as private final ITEM_NUMBER. I have a block of code that does this task in a rather ugly and roundabout manner, and I'm sure there's a more concise and correct way to do so.

Here is the relevant code in the InventoryItem class, which has the UPC variable. Is there a different, more concise way to do this, regarding the section which extracts numbers from UPC? 

public InventoryItem(
        long UPC, 
        Category category, 
        Unit_Of_Measure unitOfMeasure, 
        String binLocation, 
        String aisle, 
        String name, 
        String description, 
        short itemsPerUOM,
        int unitsInStock,
        int unitsLastReceived){

    this.UPC = UPC;
    this.category = category;
    this.unitOfMeasure = unitOfMeasure;
    this.binLocation = binLocation;
    this.aisle = aisle;
    this.name = name;
    this.description = description;
    this.itemsPerUOM = itemsPerUOM;
    this.unitsInStock = unitsInStock;
    this.unitsLastReceived = unitsLastReceived;


    /* The code block below parses and extracts digits 1-6 of a UPC which is
     * the unique manufacturer ID. This block also repeats the same process for
     * digits 7-11 which are the manufacturer-specific Item Number. After these
     * steps, the temp Strings are converted to their long integer values and
     * used to initialize MANUFACTURER_ID and ITEM_NUMBER. The 12th digit of a 
     * UPC is used for checksum and thus is ignored for the scope of this program */


    String str = Long.toString(UPC);
    String tempManufacturerID = "";
    String tempItemNumber = "";
    char[] chArr = str.toCharArray();

    //extract the manufacturer ID
    for(int i = 0; i < 6; i++){
        tempManufacturerID += String.valueOf(chArr[i]);
    }

    //extract the manufacturer's item number
    for(int i = 6; i < 11; i++){
        tempItemNumber += String.valueOf(chArr[i]);
    }

    // unbox and assign the extracted data to their respective variables
    MANUFACTURER_ID = Integer.valueOf(tempManufacturerID);
    ITEM_NUMBER = Integer.valueOf(tempItemNumber); 

}

.

.

SOLUTION

public InventoryItem(
        long UPC, 
        Category category, 
        Unit_Of_Measure unitOfMeasure, 
        String binLocation, 
        String aisle, 
        String name, 
        String description, 
        short itemsPerUOM,
        int unitsInStock,
        int unitsLastReceived){

    this.UPC = UPC;
    this.category = category;
    this.unitOfMeasure = unitOfMeasure;
    this.binLocation = binLocation;
    this.aisle = aisle;
    this.name = name;
    this.description = description;
    this.itemsPerUOM = itemsPerUOM;
    this.unitsInStock = unitsInStock;
    this.unitsLastReceived = unitsLastReceived;
    this.MANUFACTURER_ID = (int)(this.UPC / 1000000); // <--So much nicer!
    this.ITEM_NUMBER = (int)((this.UPC % 1000000) / 10); // <--So much nicer!

}

Upvotes: 0

Views: 124

Answers (4)

Andrzej Bobak
Andrzej Bobak

Reputation: 2112

How about a simple arithmetic mod / div action?

long manufacturerID = (long) UPC / 1000000L;
long itemNumber = (long) (UPC % 100000L) / 10;

Simple arithmetic without costly string operations is much better performance wise. It also looks far more elegant.

Upvotes: 1

Szymon
Szymon

Reputation: 43023

You can do it on integers/longs:

long longcode = 123456789012L;
long firstpart = longcode / 1000000L;
long secondpart = (longcode - 1000000L * firstpart) / 10L;

On strings, you can use substring() to get the string parts:

String str = Long.toString(UPC);
String tempManufacturerID = str.substring(0,6);
String tempItemNumber = str.substring(6,11);

Upvotes: 1

Arjit
Arjit

Reputation: 3456

use substring method of String class. like

 `String tempManufacturerID = str.substring(0,7);`  //First 7 digits from index pos - 0 to pos - 6

Upvotes: 0

Orel Eraki
Orel Eraki

Reputation: 12196

Java has a String built in method called substring.

String c = "abc".substring(2,3); // Output: b

Upvotes: 0

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