wrong_code stringlengths 3 123 | correct_code stringlengths 3 155 | explanation stringclasses 101
values | language stringclasses 26
values |
|---|---|---|---|
if temp > 79
puts 'output' | if temp > 79
puts 'output'
end | Add 'end'. | Ruby |
void main() {{ print('output') }} | void main() {{ print('output'); }} | Add semicolon. | Dart |
var x = 5; x = true | var x = 5; x = 10 | Type mismatch. | Kotlin |
list:
- item1
- item2 | list:
- item1
- item2 | Correct. | YAML |
["test", 51] | ["test", 51] | Correct. | JSON |
switch(c){{ case 68: break; }} | switch(c){{ case 68: break; default: break; }} | Add default case. | Java |
<hr></hr> | <hr> | Self-closing. | HTML |
const obj:Person = {{name:'hello'}}; | const obj:Person = {{name:'hello', age:38}}; | Add missing property. | TypeScript |
var a int = 'hello' | var a string = 'hello' | Type mismatch. | Go |
for i in $(ls); do echo $i; done | for i in $(ls); do echo $i; done | Correct. | Shell |
'hello' + 77 | 'hello' + str(77) | Can't add int to string. | Python |
test | test() | Add parentheses. | Swift |
x <- 5; if (x > 3) print('large') | x <- 5; if (x > 3) print('large') | Correct. | R |
75y = 10 | y75 = 10 | Variable cannot start with digit. | Python |
int c = 'result'; | String c = 'result'; | Type mismatch. | Dart |
package main
func main() {{}} | package main
import 'fmt'
func main() {{}} | Import needed. | Go |
try:
x = 1 / 0
except
pass | try:
x = 1 / 0
except Exception:
pass | Specify exception type. | Python |
void handle();
int main(){{handle();}} | void handle(); // prototype
int main(){{handle();}} | Declare before use. | C++ |
let temp = 79; temp += 1; | let mut temp = 79; temp += 1; | Need mut to modify. | Rust |
{{'status':12, 'status' 12}} | {{'status':12, 'status':12}} | Colon missing. | Python |
cin >> bar; | int bar;
cin >> bar; | Declare variable. | C++ |
let str1 = String::from("world"); let str2 = str1; println!("{{}}", str1); | let str1 = String::from("world"); let str2 = str1.clone(); println!("{{}}", str1); | Clone to avoid move. | Rust |
p {{ color: #fff }} | p {{ color: #fff; }} | Add semicolon. | CSS |
#content {{ color: green; }} | #content {{ color: green; }} | Correct. | CSS |
<center>data</center> | <div style='text-align:center;'>data</div> | Use CSS. | HTML |
int arr[93]; arr[93]=5; | int arr[93]; if(93<93){{}} else arr[93]=5; | Bounds check. | C++ |
ArrayList list = new ArrayList(); | ArrayList<String> list = new ArrayList<>(); | Use generics. | Java |
for (int i=0; i<16; i++) {{}} | for (int i=0; i<16; i++) {{}} | Correct. | Java |
$x = 5; echo $x | $x = 5; echo $x; | Missing semicolon. | PHP |
else
print('info') | else:
print('info') | Colon after else. | Python |
fn render() -> i32 {{ 48 }} | fn render() -> i32 {{ 48 }} | Correct. | Rust |
b > 22 & y < 82 | b > 22 and y < 82 | Use 'and' not '&'. | Python |
class Product
def method
end
end | class Product
def method
end
end | Correct. | Ruby |
User.save(); | User.save().then(()=>{{}}).catch(err=>{{}}); | Handle promise. | Node.js |
Write-Host 'message' | Write-Host 'message' | Correct. | PowerShell |
class Child Base: | class Child(Base): | Inheritance uses parentheses. | Python |
int &ref; | int x; int &ref = x; | Reference must be initialized. | C++ |
try {{ throw 'hello'; }} catch(e) {{}} | try {{ throw new Error('hello'); }} catch(e) {{}} | Throw Error objects. | JavaScript |
SELECT * FROM items WHRE age=65; | SELECT * FROM items WHERE age=65; | Fix WHERE. | SQL |
print 'info' | print('info') | print needs parentheses. | Python |
if [ $data = 45 ]; then | if [ "$data" = 45 ]; then | Quote variable. | Shell |
with open('log.txt') as fp:
data = fp.read() | with open('log.txt') as fp:
data = fp.read() | Correct. | Python |
const data = 56; data = 88; | let data = 56; data = 88; | Cannot reassign const. | JavaScript |
match item {{ 1 => {{}} }} | match item {{ 1 => {{}} _ => {{}} }} | Match must be exhaustive. | Rust |
print('test') | print('test') | Correct. | R |
while item > 24
item -= 1 | while item > 24:
item -= 1 | Colon missing after while. | Python |
$index = 48; if ($index = 48) {{}} | $index = 48; if ($index == 48) {{}} | Use ==. | PHP |
function render(val:string){{return val;}} render(67); | function render(val:string){{return val;}} render('message'); | Pass correct type. | TypeScript |
function process(): void {{ return 17; }} | function process(): number {{ return 17; }} | Return type mismatch. | TypeScript |
var x = 5; x = "hello" | var x = "hello" | Type mismatch. | Swift |
x := 84 | x := 84 | Correct. | Go |
name: test
age: 77 | name: test
age: 77 | Correct. | YAML |
SELECT COUNT(*) FROM users | SELECT COUNT(*) FROM users; | Missing semicolon. | SQL |
<br></br> | <br> | Self-closing. | HTML |
type MyType = string | number; let x: MyType = true; | type MyType = string | number; let x: MyType = 'hello'; | Type not in union. | TypeScript |
// comment | /* comment */ | Use /* */. | CSS |
public static void main(String[] args) {{}} | public static void main(String[] args) {{}} | Correct. | Java |
if (c = 41) {{}} | if (c == 41) {{}} | Use ==. | Kotlin |
let mut y=26; let r1=&mut y; let r2=&mut y; | let mut y=26; {{ let r1=&mut y; }} let r2=&mut y; | Only one mutable borrow. | Rust |
var x int | var x int | Correct. | Go |
{{"value":"hello",}} | {{"value":"hello"}} | Remove trailing comma. | JSON |
let y = 'info' | let y = "info" | Double quotes. | Swift |
if num = 6 {{}} | if num == 6 {{}} | Use ==. | Swift |
.Person {{ color: #fff; }} | .Person {{ color: #fff; }} | Correct. | CSS |
'value' + 39 | 'value' + 39.to_s | Convert int. | Ruby |
sys.sqrt(90) | import sys
sys.sqrt(90) | Import module first. | Python |
for index in range(30)
print(index) | for index in range(30):
print(index) | Colon after for. | Python |
yield temp | yield temp | Correct yield. | Python |
disp('message') | disp('message') | Correct. | MATLAB |
INSERT INTO orders VALUES ('output',47) | INSERT INTO orders (name, status) VALUES ('output',47); | Specify columns. | SQL |
let foo: i32 = "result"; | let foo: &str = "result"; | Type mismatch. | Rust |
println('message') | println("message") | Double quotes. | Scala |
let y: number | null = null; y.toFixed(51); | let y: number | null = null; if(y!==null) y.toFixed(51); | Null check. | TypeScript |
<input type='text' value='world'> | <input type='text' value='world' name='name'> | Add name attribute. | HTML |
local index = 41 | local index = 41 | Correct. | Lua |
List(57,31,13) | List(57,31,13) | Correct. | Scala |
if temp = 73: | if temp == 73: | Use == for comparison. | Python |
val foo = 40; foo = 75 | var foo = 40; foo = 75 | Use var for reassignment. | Scala |
{{"status":"result" "age":14}} | {{"status":"result", "age":14}} | Add comma. | JSON |
def bar
puts 'test'
end | def bar
puts 'test'
end | Correct. | Ruby |
print 'hello' | print('hello') | Parentheses for function call. | Lua |
<div><p>world</div></p> | <div><p>world</p></div> | Nest properly. | HTML |
fmt.Println 'value' | fmt.Println('value') | Missing parentheses. | Go |
SELECT age email FROM users; | SELECT age, email FROM users; | Add comma. | SQL |
if (val = 42) {{}} | if (val == 42) {{}} | Use ==. | Java |
class Product {{ int temp; }}
obj.temp=5; | class Product {{ public int temp; }}
obj.temp=5; | Make field public. | Java |
h1 {{ font-size:79px color:red; }} | h1 {{ font-size:79px; color:red; }} | Add semicolon. | CSS |
{{'age':'data'}} | {{"age":"data"}} | Use double quotes. | JSON |
if ($val = 12) | if ($val == 12) | Use ==. | Perl |
arr[74] | if arr.indices.contains(74) {{ arr[74] }} | Check index. | Swift |
System.out.println('output') | System.out.println('output'); | Add semicolon. | Java |
int* p = nullptr; *p=5; | int* p = new int; *p=5; | Allocate memory. | C++ |
echo output world | echo 'output world' | Quote to prevent splitting. | Shell |
[84, 77, 58 | [84, 77, 58] | Close bracket. | Python |
x = 5; if x > 3, disp('large'), end | x = 5; if x > 3, disp('large'), end | Correct. | MATLAB |
const http = require('http'); http.createServer((req,res) => res.end('world')).listen(19); | const http = require('http'); http.createServer((req,res) => res.end('world')).listen(19); | Correct. | Node.js |
<div color=#333> | <div style='color:#333;'> | Use style attribute. | CSS |
if result = 50 | if result == 50 | Use ==. | MATLAB |
const int x; x = 5; | const int x = 5; | Const must be initialized. | C++ |
$list[55] | if ($list.Count -gt 55) {{ $list[55] }} | Check bounds. | PowerShell |
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