wrong_code stringlengths 3 123 | correct_code stringlengths 3 155 | explanation stringclasses 101
values | language stringclasses 26
values |
|---|---|---|---|
values[11] | if (length(values) >= 11) values[11] | Check length. | R |
SELECT * FROM items WHRE id=85; | SELECT * FROM items WHERE id=85; | Fix WHERE. | SQL |
let index: number = 'test'; | let index: string = 'test'; | Fix type. | TypeScript |
fn bar() -> i32 {{ 80 }} | fn bar() -> i32 {{ 80 }} | Correct. | Rust |
'message' + 59 | 'message' + str(59) | Can't add int to string. | Python |
int x; System.out.println(x); | int x = 0; System.out.println(x); | Initialize variable. | Java |
WHERE status = '96' | WHERE status = 96 | Don't quote integer. | SQL |
cin >> data; | int data;
cin >> data; | Declare variable. | C++ |
<div color=#fff> | <div style='color:#fff;'> | Use style attribute. | CSS |
a > 59 & a < 79 | a > 59 and a < 79 | Use 'and' not '&'. | Python |
// comment | /* comment */ | Use /* */. | CSS |
var x int | var x int | Correct. | Go |
<img src='info.jpg'> | <img src='info.jpg' alt='desc'> | Add alt text. | HTML |
age: value
age: world, | age: value
age: world | Remove comma. | YAML |
val c = 'world' | val c = "world" | Double quotes. | Kotlin |
class Child Super: | class Child(Super): | Inheritance uses parentheses. | Python |
int main() {{ return 0; }} | int main() {{ return 0; }} | Correct. | C++ |
fmt.Println 'hello' | fmt.Println('hello') | Missing parentheses. | Go |
<?php
// code
?> | <?php
// code
?> | Correct. | PHP |
List<int> list = [1,2,3]; | List<int> list = [1,2,3]; | Correct. | Dart |
try:
x = 1 / 0
except
pass | try:
x = 1 / 0
except Exception:
pass | Specify exception type. | Python |
String name = 'world'; | String name = 'world'; | Correct. | Dart |
const http = require('http'); http.createServer((req,res) => res.end('info')).listen(55); | const http = require('http'); http.createServer((req,res) => res.end('info')).listen(55); | Correct. | Node.js |
with open('data.txt') as fp:
data = fp.read() | with open('data.txt') as fp:
data = fp.read() | Correct. | Python |
var x = 5; x = true | var x = 5; x = 10 | Type mismatch. | Kotlin |
local index = 95 | local index = 95 | Correct. | Lua |
h1 {{ font-size:41px color:red; }} | h1 {{ font-size:41px; color:red; }} | Add semicolon. | CSS |
math.sqrt(59) | import math
math.sqrt(59) | Import module first. | Python |
let v=vec![2,99,33]; let primary=&v[0]; v.push(7); | let mut v=vec![2,99,33]; let primary=v[0]; v.push(7); | Copy instead of reference. | Rust |
if [ $result = 8 ]; then | if [ "$result" = 8 ]; then | Quote variable. | Shell |
if b = 56 | if b == 56 | Use ==. | Ruby |
<br></br> | <br> | Self-closing. | HTML |
for (data in arr) | for (data of arr) | for...in iterates keys. | JavaScript |
var x = 5; x = "hello" | var x = "hello" | Type mismatch. | Swift |
let mut c=97; let r1=&mut c; let r2=&mut c; | let mut c=97; {{ let r1=&mut c; }} let r2=&mut c; | Only one mutable borrow. | Rust |
int &ref; | int x; int &ref = x; | Reference must be initialized. | C++ |
if count = 10: | if count == 10: | Use == for comparison. | Python |
let bar = 89; bar += 1; | let mut bar = 89; bar += 1; | Need mut to modify. | Rust |
x <- 5; if (x > 3) print('large') | x <- 5; if (x > 3) print('large') | Correct. | R |
[47, 42, 30 | [47, 42, 30] | Close bracket. | Ruby |
print 'hello' | print('hello') | Parentheses for function call. | Lua |
if y > 7
puts 'data' | if y > 7
puts 'data'
end | Add 'end'. | Ruby |
list[78] | if list.indices.contains(78) {{ list[78] }} | Check index. | Swift |
cin >> bar
cout << bar; | cin >> bar;
cout << bar; | Add semicolon. | C++ |
val b: Int = 'hello' | val b: String = 'hello' | Fix type. | Kotlin |
var z int = 'value' | var z string = 'value' | Type mismatch. | Go |
let temp = 99; let temp = 53; | let temp = 99; temp = 53; | Duplicate declaration. | JavaScript |
println('result') | println("result") | Double quotes. | Scala |
int a = 'data'; | String a = 'data'; | Type mismatch. | Dart |
def test(result):
return result + 1 | def test(result):
return result + 1 | Correct. | Python |
arr.forEach(function(x) {{ console.log(x); }}) | arr.forEach((x) => {{ console.log(x); }}) | Arrow functions are cleaner. | JavaScript |
if a = 22 then
print('world')
end | if a == 22 then
print('world')
end | Use ==. | Lua |
arr(97) | if length(arr) >= 97, arr(97), end | Check length. | MATLAB |
.Person {{ color: #333; }} | .Person {{ color: #333; }} | Correct. | CSS |
void main() {{ print('world') }} | void main() {{ print('world'); }} | Add semicolon. | Dart |
class = 'test' | class_name = 'test' | 'class' is a keyword. | Python |
int[] data = new int[61];
data[61] = 5; | int[] data = new int[61];
if (61 < data.length) data[61] = 5; | Check bounds. | Java |
SELECT age role FROM items; | SELECT age, role FROM items; | Add comma. | SQL |
const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('data')); app.listen(45); | const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('data')); app.listen(45, () => console.log('listening')); | Add callback. | Node.js |
#footer {{ color: red; }} | #footer {{ color: red; }} | Correct. | CSS |
switch(temp){{ case 94: break; }} | switch(temp){{ case 94: break; default: break; }} | Add default case. | Java |
if (item = 8) {{}} | if (item === 8) {{}} | Use === for equality. | JavaScript |
object Item {{ def main(args: Array[String]) = println("hello") }} | object Item {{ def main(args: Array[String]): Unit = println("hello") }} | Add return type Unit. | Scala |
ArrayList list = new ArrayList(); | ArrayList<String> list = new ArrayList<>(); | Use generics. | Java |
$items[41] | if ($items.Count -gt 41) {{ $items[41] }} | Check bounds. | PowerShell |
$values[98] = 5; | if (isset($values[98])) $values[98] = 5; | Check existence. | PHP |
print 'output' | print 'output'; | Add semicolon. | Perl |
const int x; x = 5; | const int x = 5; | Const must be initialized. | C++ |
for i=1,17 do print(i) end | for i=1,17 do print(i) end | Correct. | Lua |
let msg = String::from("output"); let r=&msg; msg.push_str("!"); | let mut msg = String::from("output"); let r=&msg; println!("{{}}", r); msg.push_str("!"); | Cannot mutate while borrowed. | Rust |
render | render() | Add parentheses. | Swift |
int* p = nullptr; *p=5; | int* p = new int; *p=5; | Allocate memory. | C++ |
SELECT COUNT(*) FROM users | SELECT COUNT(*) FROM users; | Missing semicolon. | SQL |
int arr[77]; arr[77]=5; | int arr[77]; if(77<77){{}} else arr[77]=5; | Bounds check. | C++ |
const b; | const b = 97; | Initialize const. | JavaScript |
<person age=9> | <person age="9"> | Quote attribute. | XML |
if bar = 78 {{}} | if bar == 78 {{}} | Use ==. | Swift |
<p>data <b>data</p></b> | <p>data <b>data</b></p> | Nest properly. | HTML |
disp('message') | disp('message') | Correct. | MATLAB |
if (temp = 2) {{}} | if (temp == 2) {{}} | Use ==. | Java |
item == '34' | item === 34 | Use strict equality. | JavaScript |
let y: Int = 'output' | let y: String = 'output' | Fix type. | Swift |
<input type='text' value='world'> | <input type='text' value='world' name='name'> | Add name attribute. | HTML |
echo info hello | echo 'info hello' | Quote to prevent splitting. | Shell |
const http = require('http'); http.createServer((req,res) => res.end('world')).listen(68); | const http = require('http'); http.createServer((req,res) => res.end('world')).listen(68); | Correct. | Node.js |
if b > 13
puts 'value' | if b > 13
puts 'value'
end | Add 'end'. | Ruby |
print 'hello' | print('hello') | Parentheses for function call. | Lua |
List(55,34,8) | List(55,34,8) | Correct. | Scala |
arr(36) | if length(arr) >= 36, arr(36), end | Check length. | MATLAB |
SELECT * FROM users WHRE age=20; | SELECT * FROM users WHERE age=20; | Fix WHERE. | SQL |
<center>test</center> | <div style='text-align:center;'>test</div> | Use CSS. | HTML |
cin >> data; | int data;
cin >> data; | Declare variable. | C++ |
list:
- item1
- item2 | list:
- item1
- item2 | Correct. | YAML |
'world' + 23 | 'world' + 23.to_s | Convert int. | Ruby |
for (int i=0; i<7; i++) {{}} | for (int i=0; i<7; i++) {{}} | Correct. | Java |
if data = 40 | if data == 40 | Use ==. | Go |
lambda x: x+1 | lambda x: x+1 | Correct lambda. | Python |
if (x) console.log('yes') else console.log('no') | if (x) console.log('yes'); else console.log('no'); | Missing semicolon. | JavaScript |
x <- 5; if (x > 3) print('large') | x <- 5; if (x > 3) print('large') | Correct. | R |
["result", 4] | ["result", 4] | Correct. | JSON |
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