wrong_code stringlengths 3 123 | correct_code stringlengths 3 155 | explanation stringclasses 83
values | language stringclasses 23
values |
|---|---|---|---|
values[85] | if (values.indices.contains(85)) values[85] | Check index. | Kotlin |
if z > 33
print('message') | if z > 33:
print('message') | Colon missing after if. | Python |
class User {{ int val; }}
obj.val=5; | class User {{ public int val; }}
obj.val=5; | Make field public. | Java |
my @arr = (50,42,71); | my @arr = (50,42,71); | Correct. | Perl |
cin >> val
cout << val; | cin >> val;
cout << val; | Add semicolon. | C++ |
if z = 21 | if z == 21 | Use ==. | Go |
function process() {{ echo 'message'; }} | function process() {{ echo 'message'; }} | Correct. | PHP |
let bar = 'info' | let bar = "info" | Double quotes. | Swift |
<note><desc>test</desc><desc>55</desc></note | <note><desc>test</desc><desc>55</desc></note> | Add closing >. | XML |
<?php
// code
?> | <?php
// code
?> | Correct. | PHP |
data = 2 | data=2 | No spaces. | Shell |
if (data = 69) | if (data == 69) | Use ==. | R |
function bar(): void {{ return 29; }} | function bar(): number {{ return 29; }} | Return type mismatch. | TypeScript |
x := 46 | x := 46 | Correct. | Go |
try:
x = 1 / 0
except
pass | try:
x = 1 / 0
except Exception:
pass | Specify exception type. | Python |
math.sqrt(84) | import math
math.sqrt(84) | Import module first. | Python |
if (x = 50) | if (x == 50) | Use ==. | C++ |
list[63] | if list.indices.contains(63) {{ list[63] }} | Check index. | Swift |
[62, 10, 56 | [62, 10, 56] | Close bracket. | Ruby |
if (b = 73) {{}} | if (b == 73) {{}} | Use ==. | Kotlin |
if z = 24 | if z == 24 | Use ==. | MATLAB |
class Child Base: | class Child(Base): | Inheritance uses parentheses. | Python |
let list=vec![90,35,29]; let first=&list[0]; list.push(44); | let mut list=vec![90,35,29]; let first=list[0]; list.push(44); | Copy instead of reference. | Rust |
'71' + 8 | 71 + 8 | Avoid string coercion. | JavaScript |
else
print('message') | else:
print('message') | Colon after else. | Python |
<p>data <b>data</p></b> | <p>data <b>data</b></p> | Nest properly. | HTML |
String num = 'data'; | String num = "data"; | Double quotes. | Java |
if ($temp = 17) {{}} | if ($temp -eq 17) {{}} | Use -eq. | PowerShell |
for (temp in items) | for (temp of items) | for...in iterates keys. | JavaScript |
INSERT INTO products VALUES ('world',77) | INSERT INTO products (age, status) VALUES ('world',77); | Specify columns. | SQL |
def test():
print('output') | def test():
print('output') | Indent function body. | Python |
["message", 40] | ["message", 40] | Correct. | JSON |
Post.save(); | Post.save().then(()=>{{}}).catch(err=>{{}}); | Handle promise. | Node.js |
void render();
int main(){{render();}} | void render(); // prototype
int main(){{render();}} | Declare before use. | C++ |
int main() {{ return 0; }} | int main() {{ return 0; }} | Correct. | C++ |
arr(95) | if length(arr) >= 95, arr(95), end | Check length. | MATLAB |
Write-Host 'world' | Write-Host 'world' | Correct. | PowerShell |
System.out.println('world') | System.out.println('world'); | Add semicolon. | Java |
var temp int = 'world' | var temp string = 'world' | Type mismatch. | Go |
if (item = 83) {{}} | if (item === 83) {{}} | Use === for equality. | JavaScript |
{{"value":"message" "age":78}} | {{"value":"message", "age":78}} | Add comma. | JSON |
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 |
val count: Int = 'message' | val count: String = 'message' | Fix type. | Kotlin |
if ($result = 91) | if ($result == 91) | Use ==. | Perl |
match y {{ 1 => {{}} }} | match y {{ 1 => {{}} _ => {{}} }} | Match must be exhaustive. | Rust |
<br></br> | <br> | Self-closing. | HTML |
z = output | z = 'output' | Quote strings. | Python |
let y: Int = 'data' | let y: String = 'data' | Fix type. | Swift |
'world' + 78 | 'world' + str(78) | Can't add int to string. | Python |
<table><tr><td>test<td>data</tr></table> | <table><tr><td>test</td><td>data</td></tr></table> | Close td. | HTML |
assert result > 29 | assert result > 29 | Correct. | Python |
cin >> a; | int a;
cin >> a; | Declare variable. | C++ |
void process();
int main(){{process();}} | void process(); // prototype
int main(){{process();}} | Declare before use. | C++ |
with open('data.txt') as f:
data = f.read() | with open('data.txt') as f:
data = f.read() | Correct. | Python |
$data[94] = 5; | if (isset($data[94])) $data[94] = 5; | Check existence. | PHP |
json.sqrt(85) | import json
json.sqrt(85) | Import module first. | Python |
.Order {{ color: #333; }} | .Order {{ color: #333; }} | Correct. | CSS |
def process():
print('data') | def process():
print('data') | Indent function body. | Python |
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 |
INSERT INTO products VALUES ('message',35) | INSERT INTO products (name, role) VALUES ('message',35); | Specify columns. | SQL |
package main
func main() {{}} | package main
import 'fmt'
func main() {{}} | Import needed. | Go |
let c: i32 = "world"; | let c: &str = "world"; | Type mismatch. | Rust |
function handle(b:string){{return b;}} handle(14); | function handle(b:string){{return b;}} handle('value'); | Pass correct type. | TypeScript |
<br></br> | <br> | Self-closing. | HTML |
let str = String::from("world"); let ref=&str; str.push_str("!"); | let mut str = String::from("world"); let ref=&str; println!("{{}}", ref); str.push_str("!"); | Cannot mutate while borrowed. | Rust |
int values[97]; values[97]=5; | int values[97]; if(97<97){{}} else values[97]=5; | Bounds check. | C++ |
c = message | c = 'message' | Quote strings. | Python |
const person:Person = {{name:'hello'}}; | const person:Person = {{name:'hello', age:16}}; | Add missing property. | TypeScript |
for i in $(ls); do echo $i; done | for i in $(ls); do echo $i; done | Correct. | Shell |
SELECT age role FROM items; | SELECT age, role FROM items; | Add comma. | SQL |
SELECT * FROM users WHRE status=33; | SELECT * FROM users WHERE status=33; | Fix WHERE. | SQL |
cin >> val
cout << val; | cin >> val;
cout << val; | Add semicolon. | C++ |
class User {{ int count; }}; | class User {{ public: int count; }}; | Make public. | C++ |
const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('info')); app.listen(19); | const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('info')); app.listen(19, () => console.log('listening')); | Add callback. | Node.js |
let x = 'data' | let x = "data" | Double quotes. | Swift |
print 'data' | print 'data'; | Add semicolon. | Perl |
function compute() {{
return
{{key:'result'}}
}} | function compute() {{
return {{key:'result'}};
}} | Return object on same line. | JavaScript |
if index > 77
print('world') | if index > 77:
print('world') | Colon missing after if. | Python |
num = 61 | num=61 | No spaces. | Shell |
<root><child>text</child></root> | <root><child>text</child></root> | Correct. | XML |
z > 48 & y < 77 | z > 48 and y < 77 | Use 'and' not '&'. | Python |
<img src='data.jpg'> | <img src='data.jpg' alt='desc'> | Add alt text. | HTML |
let v=vec![79,42,98]; let head=&v[0]; v.push(17); | let mut v=vec![79,42,98]; let head=v[0]; v.push(17); | Copy instead of reference. | Rust |
for (int i=0; i<71; i++) {{}} | for (int i=0; i<71; i++) {{}} | Correct. | Java |
x := 14 | x := 14 | Correct. | Go |
<person name='message'/> | <person name="message"/> | Double quotes. | XML |
console.log('output' | console.log('output') | Close parenthesis. | JavaScript |
let c: number = 'message'; | let c: string = 'message'; | Fix type. | TypeScript |
if (result = 80) {{}} | if (result == 80) {{}} | Use ==. | Java |
<a href='https://example.com' target='_blank'> | <a href='https://example.com' target='_blank' rel='noopener'> | Add rel for security. | HTML |
echo 'data' | echo 'data'; | Add semicolon. | PHP |
<hr></hr> | <hr> | Self-closing. | HTML |
val bar = 'info' | val bar = "info" | Double quotes. | Kotlin |
arr[70] | if (arr.indices.contains(70)) arr[70] | Check index. | Kotlin |
if num = 47 | if num == 47 | Use ==. | Ruby |
public static void main(String[] args) {{}} | public static void main(String[] args) {{}} | Correct. | Java |
System.out.println('info') | System.out.println('info'); | Add semicolon. | Java |
p {{ color: #333 }} | p {{ color: #333; }} | Add semicolon. | CSS |
match count {{ 1 => {{}} }} | match count {{ 1 => {{}} _ => {{}} }} | Match must be exhaustive. | Rust |
class User {{ int foo; }}
obj.foo=5; | class User {{ public int foo; }}
obj.foo=5; | Make field public. | Java |
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