java array problem

[skeptic_rob]

---

what is the best way to learn java array ...ok ra ko basta one dimensional pero when it comes to mutiple dimensional array ma yabag ko... i need ur advice mga programmer...still a student ...and want to learn more on programming...unsa best book nga reference or ebooks ba nga angay study han ug methods sad mag libog ko gamay basta e pasa sa lain nga class...

[josephG]

Post nalng diri imong nalibgan bro, and regarding sa book sa ako lang ok kaayo ang "Java how to program" by Deitel, thick book almost ma cover gyud tanan basics-intermediate java, and lots of programming tips..

[Klave]

initializing

Object[][] doubleArray = new Object[4][5];

pede sad

int x=3;
int y=2;
Object[][] doubleArray = new Object[x][y];

pede sad ni... but wala na ko sure;

Object[][] doubleArray = {{"ngano","mani"},{"baboy","ka"}};

scanning an array

normal loop

code

for(int x=0;x<doubleArray.length;x++){
Object[] row = doubleArray[x];
for(int y=0;y<row.length;y++){
Object value = row[y];
System.out.println(x+","+y+" => "+value);
}
}

output using array above
0,0 => ngano
0,1 => mani
1,0 => baboy
1,1 => ka


*** newer type of loop w same output
int x=0;
int y=0;
for(Object[] row : doubleArray){
for(Object value : row){
System.out.println(x+","+y+" => "+value);
y++;
}
x++;
}


well the point is double loops...

[skeptic_rob]

any other idea mga bro ako kalibgan kanha pag excute ug array using methods/class ...mag libog ko kung multideminsional nah...any other idea...

[skeptic_rob]

igo ra gud ko mag tagna2x kung multi-dimensional na gud

[maddox22]

any other idea mga bro ako kalibgan kanha pag excute ug array using methods/class ...mag libog ko kung multideminsional nah...any other idea...

Assignment na ninyo brad? Usahay libug-libugun gyud ta sa mga maestro no.

In actual work, it's very seldom that you are faced with the need of multi-dimensional arrays in Java - unlike in PHP. In Java you have objects and objects can be stored in lists/arrays. Your objects can also hold lists & arrays.

So in actual work, if you find yourself battling with multi-dimensional arrays in Java, then that's a red flag for you that you're doing something wrong. Your code must be as simple and possible no matter how complex the requirements are.

---

Anyway, you need to read about the Collections framework sa Java. They gave us this wonderful framework so you wouldn't have to use those horrible multi-dimensional arrays like in PHP (again - sorry folks).

In my experience, multi-dimensional arrays are so error-prone that it makes things very very hard to maintain, specially with complex requirements. It makes things coupled and not flexible. Stay away from them as much as possible.

[Klave]

any other idea mga bro ako kalibgan kanha pag excute ug array using methods/class ...mag libog ko kung multideminsional nah...any other idea...

una...

loops are primitive so you cannot contain or break them down between classes or methods

you are using arrays because you are going to handle many instances of one kind of Object

sample

Integer[][] doubleIntegerArray = new Integer[5][4];

meaning naa ka integer array with 5 rows and 4 columns...pede rasad bali bali

Always remember containers ra na ang array
each instance of an object sulod sa array is unique thus kung ganahan ka mutawag og command sa usa ka instance either you isolate the instance by...

Integer singleInstance = doubleIntegerArray[0][0]; => first element ni...in this case null...kay wala man nato sudli atong array

though you don't have to put it in another variable...

sample ako sudlan ang first element og

doubleIntegerArray[0][0] = 1; (dili ni allowed sa older version of java because of lack of "Autocast")

doubleIntegerArray[0][0] = new Integer(1); (same ra ni og buhat sa taas pero dili ka maproblema kung kulang sa version imong java)

pwede na ka muingon og

double dblValue = doubleIntegerArray[0][0].doubleValue(); Yey ako gamit method sa integer...after akong natarung og point out nga ang ganahan nako nga element kay ang naa sa first (0) row or first (0) column.

[devnull]

@ts
na answer naka ni Klave and what maddox22 said is true as well. in actual work (java), there will be few instances where you'll need to use arrays instead of collection objects but since you are a student you cannot do away with arrays for now

this here is as good a starting java book as any. even if you're new to oop. it's downloadable and free. just start at the beginning and re-read if you must until you get that eureka moment
The Java™ Tutorials

[Klave]

@ts
na answer naka ni Klave and what maddox22 said is true as well. in actual work (java), there will be few instances where you'll need to use arrays instead of collection objects but since you are a student you cannot do away with arrays for now

this here is as good a starting java book as any. even if you're new to oop. it's downloadable and free. just start at the beginning and re-read if you must until you get that eureka moment
The Java™ Tutorials

in fairness ako ginamit na collections kay List ra gyud og Vector, Arrays kay gamay ra og gamit unya kinaraan na ayu...

[skeptic_rob]

cge lang mo post dinhi guys about inyu idea....later on or little by little i will learn about ur post dinhi