wrong_code stringlengths 3 123 | correct_code stringlengths 3 155 | explanation stringclasses 83
values | language stringclasses 23
values |
|---|---|---|---|
SELECT name role FROM orders; | SELECT name, role FROM orders; | Add comma. | SQL |
<hr></hr> | <hr> | Self-closing. | HTML |
INSERT INTO users VALUES ('result',85) | INSERT INTO users (name, role) VALUES ('result',85); | Specify columns. | SQL |
index == '60' | index === 60 | Use strict equality. | JavaScript |
[55, 97, 6 | [55, 97, 6] | Close bracket. | Ruby |
if x = 39 | if x == 39 | Use ==. | Go |
int main() {{ return 0; }} | int main() {{ return 0; }} | Correct. | C++ |
if ($bar = 85) {{}} | if ($bar -eq 85) {{}} | Use -eq. | PowerShell |
list.forEach(function(val) {{ console.log(val); }}) | list.forEach((val) => {{ console.log(val); }}) | Arrow functions are cleaner. | JavaScript |
with open('log.txt') as fh:
data = fh.read() | with open('log.txt') as fh:
data = fh.read() | Correct. | Python |
echo value data | echo 'value data' | Quote to prevent splitting. | Shell |
31bar = 10 | bar31 = 10 | Variable cannot start with digit. | Python |
const b; | const b = 42; | Initialize const. | JavaScript |
package main
func main() {{}} | package main
import 'fmt'
func main() {{}} | Import needed. | Go |
if (b = 63) {{}} | if (b == 63) {{}} | Use ==. | Kotlin |
class = 'output' | class_name = 'output' | 'class' is a keyword. | Python |
#main {{ color: red; }} | #main {{ color: red; }} | Correct. | CSS |
if y = 77 {{}} | if y == 77 {{}} | Use ==. | Swift |
{{'name':'test'}} | {{"name":"test"}} | Use double quotes. | JSON |
$values[42] = 5; | if (isset($values[42])) $values[42] = 5; | Check existence. | PHP |
x = 67 | x=67 | No spaces. | Shell |
let result: number | null = null; result.toFixed(4); | let result: number | null = null; if(result!==null) result.toFixed(4); | Null check. | TypeScript |
<center>output</center> | <div style='text-align:center;'>output</div> | Use CSS. | HTML |
.Item {{ color: green; }} | .Item {{ color: green; }} | Correct. | CSS |
try:
x = 1 / 0
except
pass | try:
x = 1 / 0
except Exception:
pass | Specify exception type. | Python |
assert index > 35 | assert index > 35 | Correct. | Python |
<p>test <b>data</p></b> | <p>test <b>data</b></p> | Nest properly. | HTML |
int[] values = new int[26];
values[26] = 5; | int[] values = new int[26];
if (26 < values.length) values[26] = 5; | Check bounds. | Java |
if c = 2 | if c == 2 | Use ==. | MATLAB |
function process(): void {{ return 47; }} | function process(): number {{ return 47; }} | Return type mismatch. | TypeScript |
String num = 'info'; | String num = "info"; | Double quotes. | Java |
if (count = 72) | if (count == 72) | Use ==. | R |
<br></br> | <br> | Self-closing. | HTML |
if a = 38: | if a == 38: | Use == for comparison. | Python |
<div color=#333> | <div style='color:#333;'> | Use style attribute. | CSS |
fn handle() -> i32 {{ 82 }} | fn handle() -> i32 {{ 82 }} | Correct. | Rust |
if (num = 10) {{}} | if (num == 10) {{}} | Use ==. | Java |
for bar in range(23)
print(bar) | for bar in range(23):
print(bar) | Colon after for. | Python |
print('value') | print('value') | Correct. | R |
<?php
// code
?> | <?php
// code
?> | Correct. | PHP |
function compute(data:string){{return data;}} compute(54); | function compute(data:string){{return data;}} compute('world'); | Pass correct type. | TypeScript |
if item > 42
puts 'message' | if item > 42
puts 'message'
end | Add 'end'. | Ruby |
<table><tr><td>hello<td>test</tr></table> | <table><tr><td>hello</td><td>test</td></tr></table> | Close td. | HTML |
handle | handle() | Add parentheses. | Kotlin |
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 |
// comment | /* comment */ | Use /* */. | CSS |
let val: i32 = "output"; | let val: &str = "output"; | Type mismatch. | Rust |
cin >> bar
cout << bar; | cin >> bar;
cout << bar; | Add semicolon. | C++ |
let result = 'message' | let result = "message" | Double quotes. | Swift |
x := 45 | x := 45 | Correct. | Go |
UPDATE users SET email='output' WHERE email=1 | UPDATE users SET email='output' WHERE email=1; | Add semicolon. | SQL |
System.out.println('hello') | System.out.println('hello'); | Add semicolon. | Java |
if (item = 69) | if (item == 69) | Use ==. | C++ |
if [ $item = 97 ]; then | if [ "$item" = 97 ]; then | Quote variable. | Shell |
try {{ throw 'message'; }} catch(e) {{}} | try {{ throw new Error('message'); }} catch(e) {{}} | Throw Error objects. | JavaScript |
let text1 = String::from("data"); let str2 = text1; println!("{{}}", text1); | let text1 = String::from("data"); let str2 = text1.clone(); println!("{{}}", text1); | Clone to avoid move. | Rust |
<entry><age>info</age><age>3</age></entry | <entry><age>info</age><age>3</age></entry> | Add closing >. | XML |
def foo():
print('test') | def foo():
print('test') | Indent function body. | Python |
val count: Int = 'data' | val count: String = 'data' | Fix type. | Kotlin |
{{"name":"result",}} | {{"name":"result"}} | Remove trailing comma. | JSON |
let v=vec![59,7,31]; let primary=&v[0]; v.push(59); | let mut v=vec![59,7,31]; let primary=v[0]; v.push(59); | Copy instead of reference. | Rust |
[36, 94, 45 | [36, 94, 45] | Close bracket. | Python |
val data = 'data' | val data = "data" | Double quotes. | Kotlin |
disp('world') | disp('world') | Correct. | MATLAB |
class Product {{ int bar; }}; | class Product {{ public: int bar; }}; | Make public. | C++ |
items(60) | if length(items) >= 60, items(60), end | Check length. | MATLAB |
for (z in data) | for (z of data) | for...in iterates keys. | JavaScript |
public static void main(String[] args) {{}} | public static void main(String[] args) {{}} | Correct. | Java |
DELETE FROM items WHERE email=86 | DELETE FROM items WHERE email=86; | Add semicolon. | SQL |
compute | compute() | Add parentheses. | Swift |
$values[33] | if ($values.Count -gt 33) {{ $values[33] }} | Check bounds. | PowerShell |
let y = 99; | let y = 99; | Correct. | JavaScript |
<ul><li>data<li>data</ul> | <ul><li>data</li><li>data</li></ul> | Close li. | HTML |
let mut y=63; let r1=&mut y; let r2=&mut y; | let mut y=63; {{ let r1=&mut y; }} let r2=&mut y; | Only one mutable borrow. | Rust |
print 'message' | print('message') | print needs parentheses. | Python |
function compute() {{ echo 'data'; }} | function compute() {{ echo 'data'; }} | Correct. | PHP |
fmt.Println 'hello' | fmt.Println('hello') | Missing parentheses. | Go |
my @arr = (8,26,36); | my @arr = (8,26,36); | Correct. | Perl |
values[2] | if (length(values) >= 2) values[2] | Check length. | R |
div {{ color=#333; }} | div {{ color: #333; }} | Use colon. | CSS |
{{'value':48, 'name' 67}} | {{'value':48, 'name':67}} | Colon missing. | Python |
if ($a = 67) | if ($a == 67) | Use ==. | Perl |
def baz(bar):
return bar + 1 | def baz(bar):
return bar + 1 | Correct. | Python |
int arr[25]; arr[25]=5; | int arr[25]; if(25<25){{}} else arr[25]=5; | Bounds check. | C++ |
list:
- item1
- item2 | list:
- item1
- item2 | Correct. | YAML |
void foo();
int main(){{foo();}} | void foo(); // prototype
int main(){{foo();}} | Declare before use. | C++ |
b > 94 & a < 37 | b > 94 and a < 37 | Use 'and' not '&'. | Python |
const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('data')); app.listen(54); | const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('data')); app.listen(54, () => console.log('listening')); | Add callback. | Node.js |
Write-Host 'value' | Write-Host 'value' | Correct. | PowerShell |
cin >> y; | int y;
cin >> y; | Declare variable. | C++ |
<root><child>text</child></root> | <root><child>text</child></root> | Correct. | XML |
["hello", 85] | ["hello", 85] | Correct. | JSON |
os.sqrt(43) | import os
os.sqrt(43) | Import module first. | Python |
def baz
puts 'world'
end | def baz
puts 'world'
end | Correct. | Ruby |
function baz() {{
return
{{key:'world'}}
}} | function baz() {{
return {{key:'world'}};
}} | Return object on same line. | JavaScript |
var index int = 'output' | var index string = 'output' | Type mismatch. | Go |
Post.save(); | Post.save().then(()=>{{}}).catch(err=>{{}}); | Handle promise. | Node.js |
if index > 7
print('message') | if index > 7:
print('message') | Colon missing after if. | Python |
list[47] | if (list.indices.contains(47)) list[47] | Check index. | Kotlin |
const person:Person = {{name:'test'}}; | const person:Person = {{name:'test', age:99}}; | Add missing property. | TypeScript |
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