Logo

Programming-Idioms

This language bar is your friend. Select your favorite languages!

Idiom #356 Parse list of integers

Create the list of integers items for the string s containing integers separated by one or more whitespace characters (space, tab, newline).

from string import whitespace as ws
items, x, n = [], 0, len(s)
while x != n:
    if s[x] not in ws:
        for y in range(x + 1, n + 1):
            if y == n or s[y] in ws:
                break
        items.append(int(s[x:y]))
        x = y - 1
    x += 1
items = [*map(int, s.split())]
items = [int(x) for x in s.split()]
#include <string>
#include <vector>
using namespace std;
vector<int> items;
int x, y, n (s.length()), i;
for (x = 0; x not_eq n; ++x)
    if (not isspace(s[x])) {
        for (y = x + 1; y not_eq n; ++y)
            if (isspace(s[y])) break;
        i = stoi(s.substr(x, y - x));
        items.push_back(i);
        x = y - 1;
    }
import "fmt"
import "strconv"
parts := strings.Fields(s)
items := make([]int, len(parts))
for i, part := range parts {
	v, err := strconv.Atoi(part)
	if err != nil {
		return err
	}
	items[i] = v
}
import java.util.Scanner;
var items
    = new Scanner(s)
        .useDelimiter("\\s+")
        .tokens()
        .map(Integer::valueOf)
        .toList();
import static java.util.Collections.list;
import java.util.StringTokenizer;
var items
    = list(new StringTokenizer(s))
        .stream()
        .map(String::valueOf)
        .mapToInt(Integer::parseInt)
        .toArray();
import java.util.ArrayList;
import static java.util.Arrays.stream;
import static java.util.stream.Collectors.toCollection;
List<Integer> items
    = stream(s.split("\\s+"))
        .map(Integer::valueOf)
        .collect(toCollection(ArrayList::new));
import java.util.ArrayList;
import java.util.List;
import static java.lang.Character.isWhitespace;
import static java.lang.Integer.parseInt;
List<Integer> items = new ArrayList<>();
int x, y, n = s.length(), i;
for (x = 0; x != n; ++x)
    if (!isWhitespace(s.charAt(x))) {
        for (y = x + 1; y != n; ++y)
            if (isWhitespace(s.charAt(y)))
                break;
        i = parseInt(s.substring(x, y));
        items.add(i);
        x = y - 1;
    }
var
  tmp: array of string;
  items: array of integer;
...  
tmp := s.split(whitespace, TStringsplitOptions.ExcludeEmpty);
SetLength(items, Length(tmp));
for i := Low(tmp) to High(tmp) do items[i] := StrToInt(tmp[i]);
items = s.split.map(&:to_i)
let items = s
    .split_whitespace()
    .map(|x| x.parse::<i32>().unwrap())
    .collect::<Vec<i32>>();
let items = s
    .split_whitespace()
    .map(|x| x.parse::<i32>().unwrap())
    .collect::<Vec<i32>>();
New implementation...
< > ⌨
programming-idioms.org 
items, x, n = [], 0, len(s)
while x != n:
    if s[x] not in ws:
        for y in range(x + 1, n + 1):
            if y == n or s[y] in ws:
                break
        items.append(int(s[x:y]))
        x = y - 1
    x += 1
items = [*map(int, s.split())]
items = [int(x) for x in s.split()]
using namespace std;
vector<int> items;
int x, y, n (s.length()), i;
for (x = 0; x not_eq n; ++x)
    if (not isspace(s[x])) {
        for (y = x + 1; y not_eq n; ++y)
            if (isspace(s[y])) break;
        i = stoi(s.substr(x, y - x));
        items.push_back(i);
        x = y - 1;
    }
parts := strings.Fields(s)
items := make([]int, len(parts))
for i, part := range parts {
	v, err := strconv.Atoi(part)
	if err != nil {
		return err
	}
	items[i] = v
}
var items
    = new Scanner(s)
        .useDelimiter("\\s+")
        .tokens()
        .map(Integer::valueOf)
        .toList();
var items
    = list(new StringTokenizer(s))
        .stream()
        .map(String::valueOf)
        .mapToInt(Integer::parseInt)
        .toArray();
List<Integer> items
    = stream(s.split("\\s+"))
        .map(Integer::valueOf)
        .collect(toCollection(ArrayList::new));
List<Integer> items = new ArrayList<>();
int x, y, n = s.length(), i;
for (x = 0; x != n; ++x)
    if (!isWhitespace(s.charAt(x))) {
        for (y = x + 1; y != n; ++y)
            if (isWhitespace(s.charAt(y)))
                break;
        i = parseInt(s.substring(x, y));
        items.add(i);
        x = y - 1;
    }
var
  tmp: array of string;
  items: array of integer;
...  
tmp := s.split(whitespace, TStringsplitOptions.ExcludeEmpty);
SetLength(items, Length(tmp));
for i := Low(tmp) to High(tmp) do items[i] := StrToInt(tmp[i]);
items = s.split.map(&:to_i)
let items = s
    .split_whitespace()
    .map(|x| x.parse::<i32>().unwrap())
    .collect::<Vec<i32>>();
let items = s
    .split_whitespace()
    .map(|x| x.parse::<i32>().unwrap())
    .collect::<Vec<i32>>();