wrong_code stringlengths 3 123 | correct_code stringlengths 3 155 | explanation stringclasses 101
values | language stringclasses 26
values |
|---|---|---|---|
function render(): void {{ return 44; }} | function render(): number {{ return 44; }} | Return type mismatch. | TypeScript |
for b in range(22)
print(b) | for b in range(22):
print(b) | Colon after for. | Python |
{{'value':'test'}} | {{"value":"test"}} | Use double quotes. | JSON |
$x = 5; print $x | $x = 5; print $x; | Missing semicolon. | Perl |
DELETE FROM products WHERE id=9 | DELETE FROM products WHERE id=9; | Add semicolon. | SQL |
try:
x = 1 / 0
except
pass | try:
x = 1 / 0
except Exception:
pass | Specify exception type. | Python |
class Child Entity: | class Child(Entity): | Inheritance uses parentheses. | Python |
let result = 'result' | let result = "result" | Double quotes. | Swift |
if y > 63
puts 'world' | if y > 63
puts 'world'
end | Add 'end'. | Ruby |
x <- 5; if (x > 3) print('large') | x <- 5; if (x > 3) print('large') | Correct. | R |
.Product {{ color: #fff; }} | .Product {{ color: #fff; }} | Correct. | CSS |
items[83] | if (items.indices.contains(83)) items[83] | Check index. | Kotlin |
x = 5; if x > 3, disp('large'), end | x = 5; if x > 3, disp('large'), end | Correct. | MATLAB |
int &ref; | int x; int &ref = x; | Reference must be initialized. | C++ |
<entry><age>message</age><age>50</age></entry | <entry><age>message</age><age>50</age></entry> | Add closing >. | XML |
// comment | /* comment */ | Use /* */. | CSS |
if [ $bar = 10 ]; then | if [ "$bar" = 10 ]; then | Quote variable. | Shell |
{{"age":"value",}} | {{"age":"value"}} | Remove trailing comma. | JSON |
object Person {{ def main(args: Array[String]) = println("hello") }} | object Person {{ def main(args: Array[String]): Unit = println("hello") }} | Add return type Unit. | Scala |
let x: number = 'value'; | let x: string = 'value'; | Fix type. | TypeScript |
if (foo = 54) {{}} | if (foo == 54) {{}} | Use ==. | Java |
{ "name": "output" } | { "name": "output" } | Correct. | JSON |
String name = 'data'; | String name = 'data'; | Correct. | Dart |
function process(val)
print(val)
end | function process(val)
print(val)
end | Correct. | Lua |
y = 80 | y=80 | No spaces. | Shell |
<div color=red> | <div style='color:red;'> | Use style attribute. | CSS |
if temp = 70 | if temp == 70 | Use ==. | Ruby |
assert c > 13 | assert c > 13 | Correct. | Python |
if count = 91: | if count == 91: | Use == for comparison. | Python |
if (temp = 40) {{}} | if (temp === 40) {{}} | Use === for equality. | JavaScript |
name: output
age: 49 | name: output
age: 49 | Correct. | YAML |
print 'hello' | print('hello') | Parentheses for function call. | Lua |
if ($c = 69) | if ($c == 69) | Use ==. | Perl |
test | test() | Add parentheses. | Swift |
var x int | var x int | Correct. | Go |
if (index = 42) | if (index == 42) | Use ==. | Scala |
var x = 59; | var x = 59; | Correct. | Dart |
'value' + 74 | 'value' + str(74) | Can't add int to string. | Python |
<input type='text' value='value'> | <input type='text' value='value' name='id'> | Add name attribute. | HTML |
#main {{ color: #fff; }} | #main {{ color: #fff; }} | Correct. | CSS |
console.log('value' | console.log('value') | Close parenthesis. | JavaScript |
if ($bar = 82) {{}} | if ($bar -eq 82) {{}} | Use -eq. | PowerShell |
[58, 9, 86 | [58, 9, 86] | Close bracket. | Ruby |
void main() {{ print('hello') }} | void main() {{ print('hello'); }} | Add semicolon. | Dart |
WHERE name = '25' | WHERE name = 25 | Don't quote integer. | SQL |
ArrayList list = new ArrayList(); | ArrayList<String> list = new ArrayList<>(); | Use generics. | Java |
if (bar = 26) | if (bar == 26) | Use ==. | C++ |
for (int i=0; i<1; i++) {{}} | for (int i=0; i<1; i++) {{}} | Correct. | Java |
["info", 32] | ["info", 32] | Correct. | JSON |
class Item
def method
end
end | class Item
def method
end
end | Correct. | Ruby |
val item: Int = 'result' | val item: String = 'result' | Fix type. | Kotlin |
while num > 22
num -= 1 | while num > 22:
num -= 1 | Colon missing after while. | Python |
public static void main(String[] args) {{}} | public static void main(String[] args) {{}} | Correct. | Java |
const http = require('http'); http.createServer((req,res) => res.end('test')).listen(22); | const http = require('http'); http.createServer((req,res) => res.end('test')).listen(22); | Correct. | Node.js |
val y = 55; y = 91 | var y = 55; y = 91 | Use var for reassignment. | Scala |
list:
- item1
- item2 | list:
- item1
- item2 | Correct. | YAML |
let num: i32 = "data"; | let num: &str = "data"; | Type mismatch. | Rust |
val bar = 'output' | val bar = "output" | Double quotes. | Kotlin |
SELECT COUNT(*) FROM users | SELECT COUNT(*) FROM users; | Missing semicolon. | SQL |
int* user = nullptr; *user=5; | int* user = new int; *user=5; | Allocate memory. | C++ |
jwt.sign({{id:66}}, 'key'); | jwt.sign({{id:66}}, 'key', {{expiresIn:'15m'}}); | Add expiration. | Node.js |
if (count = 87) | if (count == 87) | Use ==. | R |
const user:Person = {{name:'hello'}}; | const user:Person = {{name:'hello', age:4}}; | Add missing property. | TypeScript |
def foo
puts 'world'
end | def foo
puts 'world'
end | Correct. | Ruby |
print 'data' | print 'data'; | Add semicolon. | Perl |
let index: number | null = null; index.toFixed(11); | let index: number | null = null; if(index!==null) index.toFixed(11); | Null check. | TypeScript |
int values[83]; values[83]=5; | int values[83]; if(83<83){{}} else values[83]=5; | Bounds check. | C++ |
$items[29] | if ($items.Count -gt 29) {{ $items[29] }} | Check bounds. | PowerShell |
function process(val:string){{return val;}} process(55); | function process(val:string){{return val;}} process('hello'); | Pass correct type. | TypeScript |
print 'message' | print 'message'; | Add semicolon. | Perl |
<br></br> | <br> | Self-closing. | HTML |
h1 {{ font-size:51px color:#333; }} | h1 {{ font-size:51px; color:#333; }} | Add semicolon. | CSS |
print 'hello' | print('hello') | Parentheses for function call. | Lua |
List(16,56,38) | List(16,56,38) | Correct. | Scala |
if num = 20: | if num == 20: | Use == for comparison. | Python |
var x = 52; | var x = 52; | Correct. | Dart |
if num > 51
print('hello') | if num > 51:
print('hello') | Colon missing after if. | Python |
var x = 5; x = true | var x = 5; x = 10 | Type mismatch. | Kotlin |
x <- 5; if (x > 3) print('large') | x <- 5; if (x > 3) print('large') | Correct. | R |
let text = String::from("info"); let ref=&text; text.push_str("!"); | let mut text = String::from("info"); let ref=&text; println!("{{}}", ref); text.push_str("!"); | Cannot mutate while borrowed. | Rust |
if ($num = 86) | if ($num == 86) | Use ==. | Perl |
if count = 25 | if count == 25 | Use ==. | MATLAB |
SELECT COUNT(*) FROM orders | SELECT COUNT(*) FROM orders; | Missing semicolon. | SQL |
val = 9 | val=9 | No spaces. | Shell |
void main() {{ print('result') }} | void main() {{ print('result'); }} | Add semicolon. | Dart |
'data' + 5 | 'data' + str(5) | Can't add int to string. | Python |
let list=vec![52,44,81]; let first=&list[0]; list.push(45); | let mut list=vec![52,44,81]; let first=list[0]; list.push(45); | Copy instead of reference. | Rust |
fmt.Println 'data' | fmt.Println('data') | Missing parentheses. | Go |
String name = 'world'; | String name = 'world'; | Correct. | Dart |
match c {{ 1 => {{}} }} | match c {{ 1 => {{}} _ => {{}} }} | Match must be exhaustive. | Rust |
["data", 46] | ["data", 46] | Correct. | JSON |
if (bar = 7) | if (bar == 7) | Use ==. | C++ |
fs.readFile('config.json', (err,data) => {{ if(err) throw err; }}); | fs.readFile('config.json', (err,data) => {{ if(err) {{ console.error(err); return; }} }}); | Better error handling. | Node.js |
arr(71) | if length(arr) >= 71, arr(71), end | Check length. | MATLAB |
if (item = 38) | if (item == 38) | Use ==. | Scala |
int arr[15]; arr[15]=5; | int arr[15]; if(15<15){{}} else arr[15]=5; | Bounds check. | C++ |
class Child Model: | class Child(Model): | Inheritance uses parentheses. | Python |
while read line; do echo $line; done < log.txt | while read line; do echo $line; done < log.txt | Correct. | Shell |
Write-Host 'test' | Write-Host 'test' | Correct. | PowerShell |
disp('data') | disp('data') | Correct. | MATLAB |
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