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1. Top results related to list to int array in java

   • int array to int number in Java

     Top Answer

     Answered Jan 28, 2014 · 18 votes

     Start with a result of 0. Loop through all elements of your int array. Multiply the result by 10, then add in the current number from the array. At the end of the loop, you have your result.

     • Result: 0
     • Loop 1: Result * 10 => 0, Result + 1 => 1
     • Loop 2: Result * 10 => 10, Result + 2 => 12
     • Loop 3: Result * 10 >= 120, Result + 3 => 123

     This can be generalized for any base by changing the base from 10 (here) to something else, such as 16 for hexadecimal.

     Other Answers

     Answered Jan 28, 2014 · 6 votes

     You have to cycle in the array and add the right value. The right value is the current element in the array multiplied by 10^position.

     So: ar[0]*1 + ar[1]*10 + ar[2] *100 + .....

     int res=0; for(int i=0;i<ar.length;i++) { res=res*10+ar[i]; }-

     Or

     for(int i=0,exp=ar.length-1;i<ar.length;i++,exp--) res+=ar[i]*Math.pow(10, exp);-

     Other Answers

     Answered Sep 23, 2015 · 4 votes

     First you'll have to convert every number to a string, then concatenate the strings and parse it back into an integer. Here's one implementation:

     int arrayToInt(int[] arr){ //using a Stringbuilder is much more efficient than just using += on a String. //if this confuses you, just use a String and write += instead of append. StringBuilder s = new StringBuilder(); - for (int i : arr) { s.append(i); //add all the ints to a string }- return Integer.parseInt(s.toString()); //parse integer out of the string}-

     Note that this produce an error if any of the values past the first one in your array as negative, as the minus signs will interfere with the parsing.

     This method should work for all positive integers, but if you know that all of the values in the array will only be one digit long (as they are in your example), you can avoid string operations altogether and just use basic math:

     int arrayToInt(int[] arr){ int result = 0;- //iterate backwards through the array so we start with least significant digits for (int n = arr.length - 1, i = 1; n >= 0; n --, i *= 10) { result += Math.abs(arr[n]) * i; }- if (arr[0] < 0) //if there's a negative sign in the beginning, flip the sign { result = - result; }- return result;}-

     This version won't produce an error if any of the values past the first are negative, but it will produce strange results.

     There is no builtin function to do this because the values of an array typically represent distinct numbers, rather than digits in a number.

     EDIT:

     In response to your comments, try this version to deal with longs:

     long arrayToLong(int[] arr){ StringBuilder s = new StringBuilder(); - for (int i : arr) { s.append(i); }- return Long.parseLong(s.toString());}-

     Edit 2:

     In response to your second comment:

     int[] longToIntArray(long l){ String s = String.valueOf(l); //expand number into a string- String token;- int[] result = new int[s.length() / 2]; - for (int n = 0; n < s.length()/2; n ++) //loop through and split the string { token = s.substring(n*2, (n+2)*2); result[n] = Integer.parseInt(token); //fill the array with the numbers we parse from the sections }- return result;}-

     Check all answers on Stack Overflow

     1/5

   • int... slots in java convert to list in scala

     Top Answer

     Answered Jan 13, 2011 · 4 votes

     It's a Seq[Int] in scala. You can use the loop you've got or all of the methods in Seq map, foreach, filter, etc.

     Check all answers on Stack Overflow

     2/5

   • Java: How to return int array from list of inputs?

     Top Answer

     Answered May 07, 2013 · 5 votes

     you can use List or array.

     Try this -

     public static List<Integer> getUnit(){ List<Integer> list = new ArrayList<>(); System.out.println("Enter the first number: "); list.add(scan.nextInt()); ... return list;}

     Other Answers

     Answered Jan 28, 2014 · 6 votes

     You have to cycle in the array and add the right value. The right value is the current element in the array multiplied by 10^position.

     So: ar[0]*1 + ar[1]*10 + ar[2] *100 + .....

     int res=0; for(int i=0;i<ar.length;i++) { res=res*10+ar[i]; }

     Or

     for(int i=0,exp=ar.length-1;i<ar.length;i++,exp--) res+=ar[i]*Math.pow(10, exp);-

     Other Answers

     Answered Sep 23, 2015 · 4 votes

     First you'll have to convert every number to a string, then concatenate the strings and parse it back into an integer. Here's one implementation:

     int arrayToInt(int[] arr){ //using a Stringbuilder is much more efficient than just using += on a String. //if this confuses you, just use a String and write += instead of append. StringBuilder s = new StringBuilder(); for (int i : arr) { s.append(i); //add all the ints to a string } return Integer.parseInt(s.toString()); //parse integer out of the string}

     Note that this produce an error if any of the values past the first one in your array as negative, as the minus signs will interfere with the parsing.

     This method should work for all positive integers, but if you know that all of the values in the array will only be one digit long (as they are in your example), you can avoid string operations altogether and just use basic math:

     int arrayToInt(int[] arr){ int result = 0;- //iterate backwards through the array so we start with least significant digits for (int n = arr.length - 1, i = 1; n >= 0; n --, i *= 10) { result += Math.abs(arr[n]) * i; } if (arr[0] < 0) //if there's a negative sign in the beginning, flip the sign { result = - result; } return result;}

     This version won't produce an error if any of the values past the first are negative, but it will produce strange results.

     There is no builtin function to do this because the values of an array typically represent distinct numbers, rather than digits in a number.

     EDIT:

     In response to your comments, try this version to deal with longs:

     long arrayToLong(int[] arr){ StringBuilder s = new StringBuilder(); - for (int i : arr) { s.append(i); } return Long.parseLong(s.toString());}

     Edit 2:

     In response to your second comment:

     int[] longToIntArray(long l){ String s = String.valueOf(l); //expand number into a string- String token; int[] result = new int[s.length() / 2]; for (int n = 0; n < s.length()/2; n ++) //loop through and split the string { token = s.substring(n*2, (n+2)*2); result[n] = Integer.parseInt(token); //fill the array with the numbers we parse from the sections } return result;}

     Check all answers on Stack Overflow

     3/5

   • Array in java, how to calculate hamming distance between String and int?

     Top Answer

     Answered Nov 07, 2022 · 0 votes

     import java.lang.*;public class Main { public static void main(String[] args) { String [] strInput1 = {"After ","blackboard ","Contents ","distances","Hamming "}; String [] strInput2 = {"two ","static ","array ","local ","find "}; int [] intResult = new int [strInput2.length] ; for (int i = 0 ; i< strInput2.length ; i++) { intResult[i] = Math.abs(strInput1[i].length() - strInput2[i].length()); System.out.println(intResult[i]); } }}

     Check all answers on Stack Overflow

     4/5

   • Java how to add int in an array using loop

     Top Answer

     Answered Sep 06, 2012 · 0 votes

     Remove numrays[0] and replace it with z

     int z =0;for (i = 0; i < numrays.length; i++) { z = z + numrays[i]; System.out.println("Sum:"+z);- } System.out.println("Average:"+z/numrays.length);

     Other Answers

     Answered Jan 28, 2014 · 6 votes

     You have to cycle in the array and add the right value. The right value is the current element in the array multiplied by 10^position.

     So: ar[0]*1 + ar[1]*10 + ar[2] *100 + .....

     int res=0; for(int i=0;i<ar.length;i++) { res=res*10+ar[i]; }-

     Or

     for(int i=0,exp=ar.length-1;i<ar.length;i++,exp--) res+=ar[i]*Math.pow(10, exp);-

     Other Answers

     Answered Sep 23, 2015 · 4 votes

     First you'll have to convert every number to a string, then concatenate the strings and parse it back into an integer. Here's one implementation:

     int arrayToInt(int[] arr){ //using a Stringbuilder is much more efficient than just using += on a String. //if this confuses you, just use a String and write += instead of append. StringBuilder s = new StringBuilder(); for (int i : arr) { s.append(i); //add all the ints to a string } return Integer.parseInt(s.toString()); //parse integer out of the string}

     Note that this produce an error if any of the values past the first one in your array as negative, as the minus signs will interfere with the parsing.

     This method should work for all positive integers, but if you know that all of the values in the array will only be one digit long (as they are in your example), you can avoid string operations altogether and just use basic math:

     int arrayToInt(int[] arr){ int result = 0;- //iterate backwards through the array so we start with least significant digits for (int n = arr.length - 1, i = 1; n >= 0; n --, i *= 10) { result += Math.abs(arr[n]) * i; } if (arr[0] < 0) //if there's a negative sign in the beginning, flip the sign { result = - result; } return result;}

     This version won't produce an error if any of the values past the first are negative, but it will produce strange results.

     There is no builtin function to do this because the values of an array typically represent distinct numbers, rather than digits in a number.

     EDIT:

     In response to your comments, try this version to deal with longs:

     long arrayToLong(int[] arr){ StringBuilder s = new StringBuilder(); - for (int i : arr) { s.append(i); } return Long.parseLong(s.toString());}

     Edit 2:

     In response to your second comment:

     int[] longToIntArray(long l){ String s = String.valueOf(l); //expand number into a string- String token; int[] result = new int[s.length() / 2]; for (int n = 0; n < s.length()/2; n ++) //loop through and split the string { token = s.substring(n*2, (n+2)*2); result[n] = Integer.parseInt(token); //fill the array with the numbers we parse from the sections } return result;}

     Check all answers on Stack Overflow

     5/5

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2. stackoverflow.com · questions · 960431arrays - How can I convert List<Integer> to int [] in Java ...

   stackoverflow.com · questions · 960431

   

   How can I convert a List<Integer> to int[] in Java? I'm confused because List.toArray() actually returns an Object[], which can be cast to neither Integer[] nor int[]. Right now I'm using a loop to do so: int[] toIntArray(List<Integer> list) { int[] ret = new int[list.size()]; for(int i = 0; i < ret.length; i++) ret[i] = list.get(i); return ret ...

3. Searches related to list to int array in java

   how to convert list to int array in java

   declare int array in java

4. www.geeksforgeeks.org · java-program-to-convertJava Program to Convert Integer List to Integer Array

   www.geeksforgeeks.org · java-program-to-convert

   

   Apr 25, 2023 · Apache Commons Lang’s ArrayUtils class provides toPrimitive() method that can convert an Integer array to primitive ints. We need to convert a list of integers to an Integer array first. We can use List.toArray() for easy conversion. Procedure: Use toPrimtive() method of Apache Common Lang’s; Use List.toArray() method; Example:

5. stackoverflow.com · questions · 3706470java - Convert Integer List to int array - Stack Overflow

   stackoverflow.com · questions · 3706470

   

   May 3, 2013 · You can use the toArray to get an array of Integers, ArrayUtils from the apache commons to convert it to an int[]. List<Integer> integerList = new ArrayList<Integer>(); Integer[] integerArray = integerList.toArray(new Integer[0]); int[] intArray = ArrayUtils.toPrimitive(integerArray);

6. www.techiedelight.com · convert-list-integer-array-intConvert Integer List to an int array in Java - Techie Delight

   www.techiedelight.com · convert-list-integer-array-int

   

   • Using Java 8
   • Using Apache Commons Lang
   • Using Guava Library

   We can use the Stream provided by Java 8 to convert a list of Integer to a primitive integer array in Java. We start by converting given List to Stream using List.stream() method. Now all we need to do is convert Stream to int. Please refer to thispost for a detailed explanation of it. Download Run Code Output: [1, 2, 3, ...

   See full list on techiedelight.com

   Apache Commons Lang’s ArrayUtils class provides a toPrimitive() method that can convert an Integer array to primitive ints. We need to convert a list of integers to an Integer array first. We can use List.toArray()for easy conversion. toPrimitive() throws a NullPointerExceptionif any null values are present in the list. We can filter null values be...

   See full list on techiedelight.com

   Guava’s Ints.toArray()can also convert a list of Integer to a primitive integer array. Download Code Output: [1, 2, 3, 4, 5] Ints.toArray() throws a NullPointerException if any null values are present in the list. We can filter null values before passing it to Ints.toArray()as seen in previous sections. That’s all about converting Integer List to a...

   See full list on techiedelight.com

7. www.delftstack.com · howto · javaHow to Convert ArrayList to Int Array in Java - Delft Stack

   www.delftstack.com · howto · java

   

   Feb 12, 2024 · Efficiently converting ArrayList to an int array in Java is crucial for seamless data integration. The toArray() method simplifies the process, offering a built-in solution. Explicitly specifying array types ensures compatibility.

8. beginnersbook.com · 2022 · 09Convert Integer List to int Array in Java - BeginnersBook

   beginnersbook.com · 2022 · 09

   

   Sep 23, 2022 · In this guide, we will see how to convert Integer List to int Array in Java. There are several ways, you can do this conversion, we have covered following methods: Using toArray() method; Using simple for loop; Using Stream API; 1. Using toArray() method. This is one of the simplest way of doing the ArrayList to Array conversion.

9. People also ask

   How to convert integer list to array list using Java 8?

   • So, first, we will get to know about how to convert integer list to array list using java 8. In java 8 there is a stream provided for converting a list of integer to an integer array. Procedure: Convert List to Stream using List.stream () —> Here List is calling stream () method. Now we convert Stream to int .

   Java Program to Convert Integer List to Integer Array

   www.geeksforgeeks.org/java-program-to-convert-integer-list-to-integer-array/

   See all results for this question

   How to convert a list of integer to a primitive integer array in Java?

   • We can use the Stream provided by Java 8 to convert a list of Integer to a primitive integer array in Java. We start by converting given List to Stream using List.stream() method. Now all we need to do is convert Stream to int. Please refer to this post for a detailed explanation of it.

   Convert Integer List to an int array in Java | Techie Delight

   www.techiedelight.com/convert-list-integer-array-int/

   See all results for this question

   How to create a ArrayList in Java?

   • Begin by creating an ArrayList of integers, a commonly used container in Java. For the conversion, initialize an empty int array with the same size as the ArrayList. Utilize a for loop to iterate through each element, fetching and assigning values to the corresponding index in the int array.

   How to Convert ArrayList to Int Array in Java - Delft Stack

   www.delftstack.com/howto/java/arraylist-to-int-array-in-java/

   See all results for this question

   How to convert an ArrayList of integers to an array of Integer objects?

   • The code effectively demonstrates the conversion of an ArrayList of integers to an array of Integer objects using the toArray method. The resulting array (intArray) maintains the order of elements from the original ArrayList. This approach is convenient and allows for precise control over the type of the resulting array.

   How to Convert ArrayList to Int Array in Java - Delft Stack

   www.delftstack.com/howto/java/arraylist-to-int-array-in-java/

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10. www.geeksforgeeks.org · convert-an-arraylistHow to Convert an ArrayList Containing Integers to Primitive ...

    www.geeksforgeeks.org · convert-an-arraylist

    

    Feb 9, 2024 · ArrayList can be used to add or remove an element dynamically in the Java program. It can be snipped dynamically based on the elements added or removed into the ArrayList. In this article, we will discuss how to convert an ArrayList containing Integers to a primitive int array.