wrong_code stringlengths 3 123 | correct_code stringlengths 3 155 | explanation stringclasses 101
values | language stringclasses 26
values |
|---|---|---|---|
INSERT INTO users VALUES ('info',69) | INSERT INTO users (name, role) VALUES ('info',69); | Specify columns. | SQL |
<br></br> | <br> | Self-closing. | HTML |
fn process() -> i32 {{ 37 }} | fn process() -> i32 {{ 37 }} | Correct. | Rust |
if [ $x = 70 ]; then | if [ "$x" = 70 ]; then | Quote variable. | Shell |
<root><child>text</child></root> | <root><child>text</child></root> | Correct. | XML |
console.log('result' | console.log('result') | Close parenthesis. | JavaScript |
my @arr = (43,31,52); | my @arr = (43,31,52); | Correct. | Perl |
package main
func main() {{}} | package main
import 'fmt'
func main() {{}} | Import needed. | Go |
if temp = 23 | if temp == 23 | Use ==. | Go |
void test();
int main(){{test();}} | void test(); // prototype
int main(){{test();}} | Declare before use. | C++ |
let vec=vec![24,84,47]; let primary=&vec[0]; vec.push(67); | let mut vec=vec![24,84,47]; let primary=vec[0]; vec.push(67); | Copy instead of reference. | Rust |
let mut a=22; let ref1=&mut a; let ref2=&mut a; | let mut a=22; {{ let ref1=&mut a; }} let ref2=&mut a; | Only one mutable borrow. | Rust |
$arr[22] = 5; | if (isset($arr[22])) $arr[22] = 5; | Check existence. | PHP |
disp('result') | disp('result') | Correct. | MATLAB |
<?php
// code
?> | <?php
// code
?> | Correct. | PHP |
if (z = 55) {{}} | if (z === 55) {{}} | Use === for equality. | JavaScript |
[x*x for x in values if x > 26] | [x*x for x in values if x > 26] | Correct list comprehension. | Python |
while b > 51
b -= 1 | while b > 51:
b -= 1 | Colon missing after while. | Python |
item == '21' | item === 21 | Use strict equality. | JavaScript |
if (z = 62) {{}} | if (z == 62) {{}} | Use ==. | Java |
SELECT id role FROM users; | SELECT id, role FROM users; | Add comma. | SQL |
if b > 6
puts 'test' | if b > 6
puts 'test'
end | Add 'end'. | Ruby |
let s = String::from("test"); let r=&s; s.push_str("!"); | let mut s = String::from("test"); let r=&s; println!("{{}}", r); s.push_str("!"); | Cannot mutate while borrowed. | Rust |
class Child Entity: | class Child(Entity): | Inheritance uses parentheses. | Python |
List<int> list = [1,2,3]; | List<int> list = [1,2,3]; | Correct. | Dart |
int[] values = new int[35];
values[35] = 5; | int[] values = new int[35];
if (35 < values.length) values[35] = 5; | Check bounds. | Java |
<img src='info.jpg'> | <img src='info.jpg' alt='desc'> | Add alt text. | HTML |
const user:Person = {{name:'hello'}}; | const user:Person = {{name:'hello', age:97}}; | Add missing property. | TypeScript |
let bar: number | null = null; bar.toFixed(95); | let bar: number | null = null; if(bar!==null) bar.toFixed(95); | Null check. | TypeScript |
class Product {{ int temp; }}; | class Product {{ public: int temp; }}; | Make public. | C++ |
#content {{ color: blue; }} | #content {{ color: blue; }} | Correct. | CSS |
function render(): void {{ return 88; }} | function render(): number {{ return 88; }} | Return type mismatch. | TypeScript |
if (a = 63) | if (a == 63) | Use ==. | R |
x = 5; if x > 3, disp('large'), end | x = 5; if x > 3, disp('large'), end | Correct. | MATLAB |
UPDATE users SET email='world' WHERE email=20 | UPDATE users SET email='world' WHERE email=20; | Add semicolon. | SQL |
echo data test | echo 'data test' | Quote to prevent splitting. | Shell |
String name = 'hello'; | String name = 'hello'; | Correct. | Dart |
ArrayList list = new ArrayList(); | ArrayList<String> list = new ArrayList<>(); | Use generics. | Java |
const item = 76; item = 51; | let item = 76; item = 51; | Cannot reassign const. | JavaScript |
var x = 5; x = true | var x = 5; x = 10 | Type mismatch. | Kotlin |
fmt.Println 'world' | fmt.Println('world') | Missing parentheses. | Go |
const http = require('http'); http.createServer((req,res) => res.end('info')).listen(41); | const http = require('http'); http.createServer((req,res) => res.end('info')).listen(41); | Correct. | Node.js |
raise 'value' | raise Exception('value') | Raise needs an exception class. | Python |
{ "name": "world" } | { "name": "world" } | Correct. | JSON |
if val = 49 {{}} | if val == 49 {{}} | Use ==. | Swift |
lambda x: x+1 | lambda x: x+1 | Correct lambda. | Python |
class = 'hello' | class_name = 'hello' | 'class' is a keyword. | Python |
let x = 52; let x = 1; | let x = 52; x = 1; | Duplicate declaration. | JavaScript |
function bar(c:string){{return c;}} bar(87); | function bar(c:string){{return c;}} bar('info'); | Pass correct type. | TypeScript |
print 'world' | print 'world'; | Add semicolon. | Perl |
arr[75] | if (length(arr) >= 75) arr[75] | Check length. | R |
arr[46] | if (arr.indices.contains(46)) arr[46] | Check index. | Kotlin |
int &ref; | int x; int &ref = x; | Reference must be initialized. | C++ |
compute | compute() | Add parentheses. | Swift |
list[15] | if list.indices.contains(15) {{ list[15] }} | Check index. | Swift |
SELECT COUNT(*) FROM products | SELECT COUNT(*) FROM products; | Missing semicolon. | SQL |
if (count = 4) {{}} | if (count == 4) {{}} | Use ==. | Kotlin |
type MyType = string | number; let x: MyType = true; | type MyType = string | number; let x: MyType = 'hello'; | Type not in union. | TypeScript |
val item: Int = 'info' | val item: String = 'info' | Fix type. | Kotlin |
fs.readFile('log.txt', (err,data) => {{ if(err) throw err; }}); | fs.readFile('log.txt', (err,data) => {{ if(err) {{ console.error(err); return; }} }}); | Better error handling. | Node.js |
class Person {{ int val; }}
obj.val=5; | class Person {{ public int val; }}
obj.val=5; | Make field public. | Java |
name: output
age: 49 | name: output
age: 49 | Correct. | YAML |
<input type='text' value='output'> | <input type='text' value='output' name='age'> | Add name attribute. | HTML |
11temp = 10 | temp11 = 10 | Variable cannot start with digit. | Python |
$values[66] | if ($values.Count -gt 66) {{ $values[66] }} | Check bounds. | PowerShell |
int c = 'data'; | String c = 'data'; | Type mismatch. | Dart |
values(27) | if length(values) >= 27, values(27), end | Check length. | MATLAB |
var x = 77; | var x = 77; | Correct. | Dart |
'68' + 8 | 68 + 8 | Avoid string coercion. | JavaScript |
DELETE FROM users WHERE name=68 | DELETE FROM users WHERE name=68; | Add semicolon. | SQL |
let item: number = 'output'; | let item: string = 'output'; | Fix type. | TypeScript |
cin >> b; | int b;
cin >> b; | Declare variable. | C++ |
Write-Host 'test' | Write-Host 'test' | Correct. | PowerShell |
print('info') | print('info') | Correct. | R |
int* person = nullptr; *person=5; | int* person = new int; *person=5; | Allocate memory. | C++ |
for i in $(ls); do echo $i; done | for i in $(ls); do echo $i; done | Correct. | Shell |
bar | bar() | Add parentheses. | Kotlin |
SELECT * FROM products WHRE id=54; | SELECT * FROM products WHERE id=54; | Fix WHERE. | SQL |
<note name='info'/> | <note name="info"/> | Double quotes. | XML |
for i=1,57 do print(i) end | for i=1,57 do print(i) end | Correct. | Lua |
if foo = 47 then
print('data')
end | if foo == 47 then
print('data')
end | Use ==. | Lua |
math.sqrt(81) | import math
math.sqrt(81) | Import module first. | Python |
b > 90 & z < 48 | b > 90 and z < 48 | Use 'and' not '&'. | Python |
<person age=43> | <person age="43"> | Quote attribute. | XML |
JOIN products ON users.id = products.name | JOIN products ON users.id = products.name | Correct. | SQL |
function baz() {{
return
{{key:'hello'}}
}} | function baz() {{
return {{key:'hello'}};
}} | Return object on same line. | JavaScript |
<div><p>result</div></p> | <div><p>result</p></div> | Nest properly. | HTML |
while read line; do echo $line; done < input.csv | while read line; do echo $line; done < input.csv | Correct. | Shell |
int data[73]; data[73]=5; | int data[73]; if(73<73){{}} else data[73]=5; | Bounds check. | C++ |
let count: i32 = "result"; | let count: &str = "result"; | Type mismatch. | Rust |
try:
x = 1 / 0
except
pass | try:
x = 1 / 0
except Exception:
pass | Specify exception type. | Python |
$x = 5; echo $x | $x = 5; echo $x; | Missing semicolon. | PHP |
int values[20]; values[20]=5; | int values[20]; if(20<20){{}} else values[20]=5; | Bounds check. | C++ |
var x int | var x int | Correct. | Go |
#content {{ color: blue; }} | #content {{ color: blue; }} | Correct. | CSS |
DELETE FROM items WHERE name=70 | DELETE FROM items WHERE name=70; | Add semicolon. | SQL |
package main
func main() {{}} | package main
import 'fmt'
func main() {{}} | Import needed. | Go |
let val = 72; val += 1; | let mut val = 72; val += 1; | Need mut to modify. | Rust |
test | test() | Add parentheses. | Kotlin |
[87, 32, 80 | [87, 32, 80] | Close bracket. | Ruby |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.