There is a string[] arr = {"aa-bb-cc","dd-bb-ee","aa-hh-gg"} which needs to be split on the basis of , and -. The values aa,dd,aa should be stored in one list whereas bb,hh in another list. I have written this code snippet:
String[] arr = {"aa-bb-cc","dd-bb-ee","aa-hh-gg"};
for(int i=0;i<arr.length;i++){
newArr = arr[i].split(",");
for(int j=0;j<newArr.length;j++){
resultArr = newArr[j].split("-");
appList.add(resultArr[0]);
prodList.add(resultArr[1]);
rolList.add(rresultArr[2]ol);
}
Above approach could be better if we do arr[i].split in another way so that we can run only one loop but I could not achieve that so far.
I wanted to know is there any best way to achieve the requirement.
You don't need to split it using , ,since it's not part of the String but part of the String array declaration syntax,just split it with a -
String[] arr = {"aa-bb-cc","dd-bb-ee","aa-hh-gg"};
for(int i=0;i<arr.length;i++){
newArr = arr[i].split("-");
appList.add(newArr[0]);
prodList.add(newArr[1]);
rolList.add(newArr[2]);
}
Related
I currently am running a for loop which reads a List object and then splits them into arrays. Here is the sample code:
List<String> lines = Arrays.asList("foo,foo,foo","bar,baz,foo","foo,baz,foo", "baz,baz,baz", "zab,baz,zab");
for (String line : lines){
String[] array = line.split(",");
String[] arraySplit2 = array[0].split(",");
System.out.print(Arrays.toString(arraySplit2));
}
The output is:
[foo][bar][foo][baz][zab]
I wish to concatenate the array strings into a single one under the loop so that it displays:
[foo, bar, foo, baz, zab]
I'm having a bit of trouble because the conditions of the loop prevent me from doing the increase int i trick and using System.arraycopy(). I'm open to ideas such as changing the structure of the loop itself.
You seem to be trying to create an array out of first items from each line.
First, So you need to create the result array first with the size of number of lines:
String[] result = new String[lines.size()];
int index = 0;
You do not need the second split, in the for loop populate the result array:
result[index++] = array[0]
After the loop print your result array.
Not 100% sure on what you want, but I guess something like this:
List<String> outList = new ArrayList<String>();
for (String line : lines) {
String[] array = line.split(",");
outList.add(array[0]);
}
String[] outStr = outList.toArray(new String[0]);
System.out.println(Arrays.toString(outStr));
I am trying to fill a 2D char array with 5 words. Each string must be split into single characters and fill one row of the array.
String str = "hello";
char[][] words = new char[10][5];
words[][] = str.toCharArray();
My error is at the 3rd line I don't know how to split the string "hello" into chars and fill only the 1st row of the 2-dimensional array
If you want the array to fill the first row, just asign it to the first row:
words[0] = str.toCharArray();
Since this will create a new array in the array, you should change the instantiation of words to this:
char[][] words = new char[5][];
Java has a String class. Make use of it.
Very little is known of what you want with it. But it also has a List class which I'd recommend as well. For this case, I'd recommend the ArrayList implementation.
Now onto the problem at hand, how would this code look now?
List<String> words = new ArrayList<>();
words.add("hello");
words.add("hello2");
words.add("hello3");
words.add("hello4");
words.add("hello5");
for (String s : words) {
System.out.println(s);
}
For your case if you are stuck with using arrays.
String str="hello";
char[][] words = new char[5][];
words[][] = str.toCharArray();
Use something along the line of
String str = "hello";
char[][] words = new char[5][];
words[0] = str.toCharArray();
for (int i = 0; i < 5; i++) {
System.out.println(words[i]);
}
However, why invent the wheel again? There are cases however, more can be read on the subject here.
Array versus List<T>: When to use which?
I have a String Array, map[] which looks like...
"####"
"#GB#"
"#BB#"
"####"
So map[1] = "#GB#"
How do I turn this into a 2D array so that newMap[1][1] would give me "G"?
Thanks a lot.
If you really need it, you can use String.toCharArray on each element array to convert them into an array.
String[] origArr = new String[10];
char[][] charArr = new char[10][];
for(int i = 0; i< origArr.length;i++)
charArr[i] = origArr[i].toCharArray();
If you want to break it up into String[] instead, you could use (thanks Pshemo)
String[] abc = "abc".split("(?!^)"); //-> ["a", "b", "c"]
This won't be dynamic. It will take O(n) + m to get to a character of a string. A much faster and dynamic approach would be a Hashmap where the key is the String and the value is a char array. Kind of unnecessarily complex but you get the seeking and individual letter charAts without having to go through the cumbersome process of resizing a primitive array.
I have got a Java String as follows:
C|51199120|36937872|14261248|0.73|I|102398308|6240560|96157748|0.07|J|90598564|1920184|8867 8380|0.0
I want split this using regex as String arrays:
Array1 = C,51199120,36937872,14261248,0.73
Array2 =I,102398308,6240560,96157748,0.07
Array3 =J,90598564,1920184,88678380,0.03
Can Anybody help with Java code?
I don't think it's that simple. You have two things you need to do:
Break up the input string when you encounter a letter
Break up each substring by the pipe
I'm no regex expert, but I don't think it can be a single pattern. You need two and a loop over the substrings.
You can easily split your string on subcomponents using String.split("\\|"), but regexes won't help you to group them up in different arrays, nor will it help you to convert substrings to appropriate type. You'll need a separate logic for that.
Use String.split() method.
String []ar=str.split("(?=([A-Z]))");
for(String s:ar)
System.out.println(s.replace("|",","));
Simpler to just split then loop.
More or less:
String input = ...
String[] splitted = input.split("|");
List<String[]> resultArrays = new ArrayList<String[]>();
String[] currentArray = null;
for (int i = 0; i < splitted.length; i++) {
if (i % 5 == 0) {
currentArray = new String[5];
resultArrays.put(currentArray);
}
currentArray[i%5] = splitted[i];
}
I have a list of words , there are 4 words, it cant contain more that 4 its just an example. I want to use just 2 of the words the rest of them should be ignored or deleted e.g :
String planets = "Moon,Sun,Jupiter,Mars";
String[] planetsArray = planets.split(",");
int numberOfPlanets = planetsArray.length;
the result i get is 4. How do i delete the rest of the words if my list contains more that 2 words ?
As suggested in your previous question, you can use
String[] fewPlanets = new String[]{planets[0], planets[1]};
Just make sure the planets array has 2 elements or more to avoid an ArrayIndexOutOfBoundsException. You can use length to check it: if (planets.length >= 2)
For a more sophisticated solution, you could also do this using System.arrayCopy() if you're using Java 1.5 or earlier,
int numberOfElements = 2;
String[] fewPlanets = new String[2];
System.arraycopy(planets, 0, fewPlanets, 0, numberOfElements);
or Arrays.copyOf() if you're using Java 1.6 or later:
int numberOfElements = 2;
String[] fewPlanets = Arrays.copyOf(planets, numberOfElements);
String planets = "Moon,Sun,Jupiter,Mars";
String[] planetsArray = planets.split(",");
if(planetsArray .length > 2){
String []newArr = new String[2];
newArr[0]=planetsArray [0];
newArr[1]=planetsArray [2];
planetsArray = newArr ;
}
Use Arrays.asList to get a List of Strings from String[] planetsArray.
Then use the methods of the List interface -contains,remove,add, ...- to simply do whatever you want on that List.
If you need to select the first 2 planets just copy the array:
String[] newPlanetsArray = Arrays.CopyOf(planetsArray, 2);
If you need to select 2 specific planets you can apply the following algorithm:
First, create a new array with 2 elements. Then, iterate through the elements in the original array and if the current element is a match add it to the new array (keep track of the current position in the new array to add the next element).
String[] newPlanetsArray = new String[2];
for(int i = 0, int j = 0; i < planetsArray.length; i++) {
if (planetsArray[i].equals("Jupiter") || planetsArray[i].equals("Mars")) {
newPlanetsArray[j++] = planetsArray[i];
if (j > 1)
break;
}
}
You could use an idea from How to find nth occurrence of character in a string? and avoid reading the remaining values from your comma separated string input. Simply locate the second comma and substring upto there
(Of course if your code snippet is just an example and you do not have a comma separated input, then please ignore this suggestion :)