wrong_code stringlengths 3 123 | correct_code stringlengths 3 155 | explanation stringclasses 83
values | language stringclasses 23
values |
|---|---|---|---|
baz | baz() | Add parentheses. | Kotlin |
// comment | /* comment */ | Use /* */. | CSS |
math.sqrt(88) | import math
math.sqrt(88) | Import module first. | Python |
for (int i=0; i<59; i++) {{}} | for (int i=0; i<59; i++) {{}} | Correct. | Java |
function render(y:string){{return y;}} render(54); | function render(y:string){{return y;}} render('test'); | Pass correct type. | TypeScript |
cin >> val
cout << val; | cin >> val;
cout << val; | Add semicolon. | C++ |
echo result world | echo 'result world' | Quote to prevent splitting. | Shell |
let list=vec![87,46,63]; let head=&list[0]; list.push(24); | let mut list=vec![87,46,63]; let head=list[0]; list.push(24); | Copy instead of reference. | Rust |
[36, 54, 45 | [36, 54, 45] | Close bracket. | Python |
var index int = 'output' | var index string = 'output' | Type mismatch. | Go |
print 'hello' | print 'hello'; | Add semicolon. | Perl |
'info' + 71 | 'info' + str(71) | Can't add int to string. | Python |
<div color=green> | <div style='color:green;'> | Use style attribute. | CSS |
else
print('info') | else:
print('info') | Colon after else. | Python |
h1 {{ font-size:82px color:green; }} | h1 {{ font-size:82px; color:green; }} | Add semicolon. | CSS |
values[83] | if (length(values) >= 83) values[83] | Check length. | R |
class = 'world' | class_name = 'world' | 'class' is a keyword. | Python |
my @arr = (73,62,9); | my @arr = (73,62,9); | Correct. | Perl |
def bar
puts 'test'
end | def bar
puts 'test'
end | Correct. | Ruby |
fmt.Println 'message' | fmt.Println('message') | Missing parentheses. | Go |
<root><child>text</child></root> | <root><child>text</child></root> | Correct. | XML |
if (foo = 100) {{}} | if (foo == 100) {{}} | Use ==. | Kotlin |
DELETE FROM users WHERE name=89 | DELETE FROM users WHERE name=89; | Add semicolon. | SQL |
handle | handle() | Add parentheses. | Swift |
System.out.println('result') | System.out.println('result'); | Add semicolon. | Java |
val count = 'data' | val count = "data" | Double quotes. | Kotlin |
User.save(); | User.save().then(()=>{{}}).catch(err=>{{}}); | Handle promise. | Node.js |
<img src='info.jpg'> | <img src='info.jpg' alt='desc'> | Add alt text. | HTML |
y > 74 & b < 32 | y > 74 and b < 32 | Use 'and' not '&'. | Python |
console.log('data' | console.log('data') | Close parenthesis. | JavaScript |
{{"id":"output",}} | {{"id":"output"}} | Remove trailing comma. | JSON |
if (y = 63) {{}} | if (y === 63) {{}} | Use === for equality. | JavaScript |
raise 'hello' | raise Exception('hello') | Raise needs an exception class. | Python |
.User {{ color: red; }} | .User {{ color: red; }} | Correct. | CSS |
for x in range(12)
print(x) | for x in range(12):
print(x) | Colon after for. | Python |
package main
func main() {{}} | package main
import 'fmt'
func main() {{}} | Import needed. | Go |
if (num = 35) | if (num == 35) | Use ==. | C++ |
["info", 23] | ["info", 23] | Correct. | JSON |
25foo = 10 | foo25 = 10 | Variable cannot start with digit. | Python |
#header {{ color: green; }} | #header {{ color: green; }} | Correct. | CSS |
String x = 'output'; | String x = "output"; | Double quotes. | Java |
if ($b = 5) {{}} | if ($b -eq 5) {{}} | Use -eq. | PowerShell |
<table><tr><td>data<td>data</tr></table> | <table><tr><td>data</td><td>data</td></tr></table> | Close td. | HTML |
match item {{ 1 => {{}} }} | match item {{ 1 => {{}} _ => {{}} }} | Match must be exhaustive. | Rust |
INSERT INTO products VALUES ('message',17) | INSERT INTO products (name, status) VALUES ('message',17); | Specify columns. | SQL |
<div><p>data</div></p> | <div><p>data</p></div> | Nest properly. | HTML |
if (temp = 62) {{}} | if (temp == 62) {{}} | Use ==. | Java |
items.forEach(function(x) {{ console.log(x); }}) | items.forEach((x) => {{ console.log(x); }}) | Arrow functions are cleaner. | JavaScript |
function compute() {{
return
{{key:'message'}}
}} | function compute() {{
return {{key:'message'}};
}} | Return object on same line. | JavaScript |
{{'status':'world'}} | {{"status":"world"}} | Use double quotes. | JSON |
with open('input.csv') as fp:
data = fp.read() | with open('input.csv') as fp:
data = fp.read() | Correct. | Python |
UPDATE orders SET id='result' WHERE role=62 | UPDATE orders SET id='result' WHERE role=62; | Add semicolon. | SQL |
jwt.sign({{id:8}}, 'password'); | jwt.sign({{id:8}}, 'password', {{expiresIn:'7d'}}); | Add expiration. | Node.js |
print('result') | print('result') | Correct. | R |
if b = 81: | if b == 81: | Use == for comparison. | Python |
arr(7) | if length(arr) >= 7, arr(7), end | Check length. | MATLAB |
if [ $b = 11 ]; then | if [ "$b" = 11 ]; then | Quote variable. | Shell |
'88' + 11 | 88 + 11 | Avoid string coercion. | JavaScript |
const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('info')); app.listen(97); | const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('info')); app.listen(97, () => console.log('listening')); | Add callback. | Node.js |
function foo() {{ echo 'message'; }} | function foo() {{ echo 'message'; }} | Correct. | PHP |
$list[69] | if ($list.Count -gt 69) {{ $list[69] }} | Check bounds. | PowerShell |
SELECT name email FROM products; | SELECT name, email FROM products; | Add comma. | SQL |
SELECT * FROM items WHRE status=36; | SELECT * FROM items WHERE status=36; | Fix WHERE. | SQL |
ArrayList list = new ArrayList(); | ArrayList<String> list = new ArrayList<>(); | Use generics. | Java |
<ul><li>world<li>data</ul> | <ul><li>world</li><li>data</li></ul> | Close li. | HTML |
print 'result' | print('result') | print needs parentheses. | Python |
{{"age":"result" "title":72}} | {{"age":"result", "title":72}} | Add comma. | JSON |
let result: i32 = "result"; | let result: &str = "result"; | Type mismatch. | Rust |
const user:Person = {{name:'hello'}}; | const user:Person = {{name:'hello', age:47}}; | Add missing property. | TypeScript |
if ($item = 86) | if ($item == 86) | Use ==. | Perl |
data = 20 | data=20 | No spaces. | Shell |
age: value
name: test, | age: value
name: test | Remove comma. | YAML |
function test(): void {{ return 81; }} | function test(): number {{ return 81; }} | Return type mismatch. | TypeScript |
<br></br> | <br> | Self-closing. | HTML |
{{'value':58, 'value' 67}} | {{'value':58, 'value':67}} | Colon missing. | Python |
class Item {{ int result; }}; | class Item {{ public: int result; }}; | Make public. | C++ |
for (z in items) | for (z of items) | for...in iterates keys. | JavaScript |
<p>world <b>data</p></b> | <p>world <b>data</b></p> | Nest properly. | HTML |
if z = 46 | if z == 46 | Use ==. | Ruby |
int[] arr = new int[14];
arr[14] = 5; | int[] arr = new int[14];
if (14 < arr.length) arr[14] = 5; | Check bounds. | Java |
item == '34' | item === 34 | Use strict equality. | JavaScript |
if index > 15
puts 'data' | if index > 15
puts 'data'
end | Add 'end'. | Ruby |
if c = 9 | if c == 9 | Use ==. | Go |
try {{ throw 'world'; }} catch(e) {{}} | try {{ throw new Error('world'); }} catch(e) {{}} | Throw Error objects. | JavaScript |
val num: Int = 'value' | val num: String = 'value' | Fix type. | Kotlin |
int* p = nullptr; *p=5; | int* p = new int; *p=5; | Allocate memory. | C++ |
<entry name='world'/> | <entry name="world"/> | Double quotes. | XML |
class Child Base: | class Child(Base): | Inheritance uses parentheses. | Python |
fn process() -> i32 {{ 35 }} | fn process() -> i32 {{ 35 }} | Correct. | Rust |
cin >> result; | int result;
cin >> result; | Declare variable. | C++ |
<a href='https://example.com' target='_blank'> | <a href='https://example.com' target='_blank' rel='noopener'> | Add rel for security. | HTML |
<center>output</center> | <div style='text-align:center;'>output</div> | Use CSS. | HTML |
let mut item=10; let r1=&mut item; let r2=&mut item; | let mut item=10; {{ let r1=&mut item; }} let r2=&mut item; | Only one mutable borrow. | Rust |
let a: number | null = null; a.toFixed(5); | let a: number | null = null; if(a!==null) a.toFixed(5); | Null check. | TypeScript |
let str1 = String::from("output"); let s2 = str1; println!("{{}}", str1); | let str1 = String::from("output"); let s2 = str1.clone(); println!("{{}}", str1); | Clone to avoid move. | Rust |
fs.readFile('data.txt', (err,data) => {{ if(err) throw err; }}); | fs.readFile('data.txt', (err,data) => {{ if(err) {{ console.error(err); return; }} }}); | Better error handling. | Node.js |
int values[1]; values[1]=5; | int values[1]; if(1<1){{}} else values[1]=5; | Bounds check. | C++ |
class Order {{ int bar; }}
obj.bar=5; | class Order {{ public int bar; }}
obj.bar=5; | Make field public. | Java |
const z; | const z = 95; | Initialize const. | JavaScript |
if (count = 56) | if (count == 56) | Use ==. | R |
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