I know how to read a file with Java
using Scanner
and File IOException, but the only thing I don't know is how to store the text in the files as an array.
Here is a snippet
of my code:
public static void main(String[] args) throws IOException{
// TODO code application logic here
// // read KeyWestTemp.txt
// create token1
String token1 = "";
// for-each loop for calculating heat index of May - October
// create Scanner inFile1
Scanner inFile1 = new Scanner(new File("KeyWestTemp.txt"));
// while loop
while(inFile1.hasNext()){
// how can I create array from text read?
// find next line
token1 = inFile1.nextLine();
Here is what my KeyWestTemp.txt
file contains:
70.3, 70.8, 73.8, 77.0, 80.7, 83.4, 84.5, 84.4, 83.4, 80.2, 76.3, 72.0
All you need to do is read each line and store that into ArrayList, as shown in the following example: BufferedReader bufReader = new BufferedReader(new FileReader("file. txt")); ArrayList<String> listOfLines = new ArrayList<>(); String line = bufReader. readLine(); while (line !
Use the fs. readFileSync() method to read a text file into an array in JavaScript, e.g. const contents = readFileSync(filename, 'utf-8'). split('\n') . The method will return the contents of the file, which we can split on each newline character to get an array of strings.
Java read file to String using BufferedReader BufferedReader reader = new BufferedReader(new FileReader(fileName)); StringBuilder stringBuilder = new StringBuilder(); String line = null; String ls = System. getProperty("line. separator"); while ((line = reader. readLine()) !=
We use FileReader object to load the file and BudfferedReader class to read the file. Then we start reading the file line by line readFilerow. Then we split the data by comma and save it into the array and finally print the data by index.
Stored as strings:
public class ReadTemps {
public static void main(String[] args) throws IOException {
// TODO code application logic here
// // read KeyWestTemp.txt
// create token1
String token1 = "";
// for-each loop for calculating heat index of May - October
// create Scanner inFile1
Scanner inFile1 = new Scanner(new File("KeyWestTemp.txt")).useDelimiter(",\\s*");
// Original answer used LinkedList, but probably preferable to use ArrayList in most cases
// List<String> temps = new LinkedList<String>();
List<String> temps = new ArrayList<String>();
// while loop
while (inFile1.hasNext()) {
// find next line
token1 = inFile1.next();
temps.add(token1);
}
inFile1.close();
String[] tempsArray = temps.toArray(new String[0]);
for (String s : tempsArray) {
System.out.println(s);
}
}
}
For floats:
import java.io.File;
import java.io.IOException;
import java.util.LinkedList;
import java.util.List;
import java.util.Scanner;
public class ReadTemps {
public static void main(String[] args) throws IOException {
// TODO code application logic here
// // read KeyWestTemp.txt
// create token1
// for-each loop for calculating heat index of May - October
// create Scanner inFile1
Scanner inFile1 = new Scanner(new File("KeyWestTemp.txt")).useDelimiter(",\\s*");
// Original answer used LinkedList, but probably preferable to use ArrayList in most cases
// List<Float> temps = new LinkedList<Float>();
List<Float> temps = new ArrayList<Float>();
// while loop
while (inFile1.hasNext()) {
// find next line
float token1 = inFile1.nextFloat();
temps.add(token1);
}
inFile1.close();
Float[] tempsArray = temps.toArray(new Float[0]);
for (Float s : tempsArray) {
System.out.println(s);
}
}
}
If you don't know the number of lines in your file, you don't have a size with which to init an array. In this case, it makes more sense to use a List :
List<String> tokens = new ArrayList<String>();
while (inFile1.hasNext()) {
tokens.add(inFile1.nextLine());
}
After that, if you need to, you can copy to an array :
String[] tokenArray = tokens.toArray(new String[0]);
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