I created an android working with default listview. Now I have 2 arrays declares as below. Please help to solve this issue. Thanks!
String[] item_index = {"1","2","3","4"};
String[] item_name = {"Bacon","Egg","Cheese","Tomato" };
String[] item_price = {"$2.50","$3.00","$2.70","$2.80" };
String[] item_barcode = {"T1","T2","T3","T4"};
I want to show the resule using **for loop** as below
1. T1-Bacon ($2.50)
2. T2-Egg ($3.00)
3. T3-Cheese ($2.70)
4. T4-Tomato ($2.80)
Thanks!
String is immutable whereas StringBuffer and StringBuider are mutable classes. StringBuffer is thread safe and synchronized whereas StringBuilder is not, thats why StringBuilder is more faster than StringBuffer. String concat + operator internally uses StringBuffer or StringBuilder class. So it is quite good to use StringBuilder to append string.
StringBuilder s = new StringBuilder();
String[] item_index = {"1","2","3","4"};
String[] item_name = {"Bacon","Egg","Cheese","Tomato" };
String[] item_price = {"$2.50","$3.00","$2.70","$2.80" };
String[] item_barcode = {"T1","T2","T3","T4"};
String[] ansValue = new String[item_index.length];
for(int i=0;i<item_index.length;i++){
s.setLength(0);
s.append(item_index[i]);
s.append(" . ");
s.append(item_barcode[i]);
s.append(" -");
s.append(item_name[i]);
s.append("(");
s.append(item_name[i]);
s.append(")");
ansValue[i]=s.toString();
System.out.println(s);
}
ArrayAdapter<String> adapter = new ArrayAdapter<String>(this,android.R.layout.simple_list_item_1,ansValue);
A bit naive approach but will work for arrays with same size:
String[] item_index = {"1","2","3","4"};
String[] item_name = {"Bacon","Egg","Cheese","Tomato" };
String[] item_price = {"$2.50","$3.00","$2.70","$2.80" };
String[] item_barcode = {"T1","T2","T3","T4"};
public void printer() {
for (int i = 0; i < item_index.length; i++) {
String line = String.format("%d. %s-%s (%s)", i + 1, item_barcode[i], item_name[i], item_price[i]);
// print or push to view
System.out.println(line);
}
}
If there is a chance that arrays sizes will be not the same you can try to use something like that:
public String defaultStringAtPosIfNull(String[] arr, int pos, String defaultString) {
if (pos >= arr.length) {
return defaultString;
}
return arr[pos] != null ? arr[pos] : defaultString;
}
and call it in String.format:defaultStringAtPosIfNull(item_barcode, i, "(empty)") instead calling item_barcode[i] directly.
A better coding approach would be having an Item class
public class Item {
public String name;
public String price;
public String barcode;
public String index;
public Item(String name, String price, String barcode, String index) {
this.name = name;
this.price = price;
this.barcode = barcode;
this.index = index;
}
@Override
public String toString() {
return this.index + ". " + this.barcode + "-" + this.name + " (" + this.price + ") ";
}
}
And then just have
for(Item item : items) {
System.out.println(item);
}
if all array size are same use this
for(int i=0;i<item_index.length;i++)
{
Systrem.out.println(item_index[i]+" . "+item_barcode[i]+" -"+item_name[i]+"("+item_price[i]+")");
}
Edit:
ArrayList<String> items= new ArrayList<String>();
for(int i=0;i<item_index.length;i++)
{
items.add(item_index[i]+" . "+item_barcode[i]+" -"+item_name[i]+"("+item_price[i]+")");
}
ArrayAdapter<String> itemsAdapter =
new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1, items);
Note: Make sure that all are have same size. Otherwise you will get ArrayindexOutofBounds exception.
