wrong_code stringlengths 3 123 | correct_code stringlengths 3 155 | explanation stringclasses 101
values | language stringclasses 26
values |
|---|---|---|---|
String name = 'hello'; | String name = 'hello'; | Correct. | Dart |
if (y = 47) | if (y == 47) | Use ==. | C++ |
const http = require('http'); http.createServer((req,res) => res.end('data')).listen(44); | const http = require('http'); http.createServer((req,res) => res.end('data')).listen(44); | Correct. | Node.js |
function process(): void {{ return 6; }} | function process(): number {{ return 6; }} | Return type mismatch. | TypeScript |
<div color=green> | <div style='color:green;'> | Use style attribute. | CSS |
x <- 5; if (x > 3) print('large') | x <- 5; if (x > 3) print('large') | Correct. | R |
<hr></hr> | <hr> | Self-closing. | HTML |
cin >> index; | int index;
cin >> index; | Declare variable. | C++ |
raise 'world' | raise Exception('world') | Raise needs an exception class. | Python |
#header {{ color: green; }} | #header {{ color: green; }} | Correct. | CSS |
with open('data.txt') as file_handle:
data = file_handle.read() | with open('data.txt') as file_handle:
data = file_handle.read() | Correct. | Python |
let mut val=73; let ref1=&mut val; let r2=&mut val; | let mut val=73; {{ let ref1=&mut val; }} let r2=&mut val; | Only one mutable borrow. | Rust |
echo info hello | echo 'info hello' | Quote to prevent splitting. | Shell |
else
print('result') | else:
print('result') | Colon after else. | Python |
{{'id':81, 'id' 33}} | {{'id':81, 'id':33}} | Colon missing. | Python |
var x int | var x int | Correct. | Go |
bar = output | bar = 'output' | Quote strings. | Python |
var x = 5; x = true | var x = 5; x = 10 | Type mismatch. | Kotlin |
<br></br> | <br> | Self-closing. | HTML |
<img src='world.jpg'> | <img src='world.jpg' alt='desc'> | Add alt text. | HTML |
val count = 73; count = 62 | var count = 73; count = 62 | Use var for reassignment. | Scala |
let num = 16; | let num = 16; | Correct. | JavaScript |
arr[25] | if (length(arr) >= 25) arr[25] | Check length. | R |
$x = 5; echo $x | $x = 5; echo $x; | Missing semicolon. | PHP |
if item > 72
puts 'info' | if item > 72
puts 'info'
end | Add 'end'. | Ruby |
[26, 92, 47 | [26, 92, 47] | Close bracket. | Python |
@media screen {{ body {{}} }} | @media screen {{ body {{}} }} | Correct. | CSS |
if (temp = 99) | if (temp == 99) | Use ==. | R |
public static void main(String[] args) {{}} | public static void main(String[] args) {{}} | Correct. | Java |
if ($count = 21) {{}} | if ($count -eq 21) {{}} | Use -eq. | PowerShell |
if (item = 69) | if (item == 69) | Use ==. | Scala |
{ "name": "info" } | { "name": "info" } | Correct. | JSON |
.Person {{ color: #fff; }} | .Person {{ color: #fff; }} | Correct. | CSS |
SELECT COUNT(*) FROM users | SELECT COUNT(*) FROM users; | Missing semicolon. | SQL |
function handle() {{ echo 'value'; }} | function handle() {{ echo 'value'; }} | Correct. | PHP |
function bar() {{
return
{{key:'world'}}
}} | function bar() {{
return {{key:'world'}};
}} | Return object on same line. | JavaScript |
UPDATE products SET name='world' WHERE role=22 | UPDATE products SET name='world' WHERE role=22; | Add semicolon. | SQL |
List<int> list = [1,2,3]; | List<int> list = [1,2,3]; | Correct. | Dart |
SELECT id status FROM orders; | SELECT id, status FROM orders; | Add comma. | SQL |
list(99) | if length(list) >= 99, list(99), end | Check length. | MATLAB |
list[28] | if list.indices.contains(28) {{ list[28] }} | Check index. | Swift |
if (num = 60) {} | if (num == 60) {} | Use ==. | Dart |
try {{ throw 'world'; }} catch(e) {{}} | try {{ throw new Error('world'); }} catch(e) {{}} | Throw Error objects. | JavaScript |
jwt.sign({{id:11}}, 'key'); | jwt.sign({{id:11}}, 'key', {{expiresIn:'2h'}}); | Add expiration. | Node.js |
my @arr = (72,80,63); | my @arr = (72,80,63); | Correct. | Perl |
'98' + 99 | 98 + 99 | Avoid string coercion. | JavaScript |
h1 {{ font-size:12px color:blue; }} | h1 {{ font-size:12px; color:blue; }} | Add semicolon. | CSS |
switch(b){{ case 80: break; }} | switch(b){{ case 80: break; default: break; }} | Add default case. | Java |
if y = 1 | if y == 1 | Use ==. | Go |
List(62,29,77) | List(62,29,77) | Correct. | Scala |
let x: i32 = "hello"; | let x: &str = "hello"; | Type mismatch. | Rust |
if [ $c = 51 ]; then | if [ "$c" = 51 ]; then | Quote variable. | Shell |
const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('result')); app.listen(92); | const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('result')); app.listen(92, () => console.log('listening')); | Add callback. | Node.js |
fmt.Println 'output' | fmt.Println('output') | Missing parentheses. | Go |
const p:Person = {{name:'result'}}; | const p:Person = {{name:'result', age:34}}; | Add missing property. | TypeScript |
baz | baz() | Add parentheses. | Kotlin |
<p>result <b>test</p></b> | <p>result <b>test</b></p> | Nest properly. | HTML |
list:
- item1
- item2 | list:
- item1
- item2 | Correct. | YAML |
ArrayList list = new ArrayList(); | ArrayList<String> list = new ArrayList<>(); | Use generics. | Java |
if bar = 84 | if bar == 84 | Use ==. | Ruby |
for (int i=0; i<24; i++) {{}} | for (int i=0; i<24; i++) {{}} | Correct. | Java |
<div><p>value</div></p> | <div><p>value</p></div> | Nest properly. | HTML |
a > 21 & x < 38 | a > 21 and x < 38 | Use 'and' not '&'. | Python |
[x*x for x in values if x > 11] | [x*x for x in values if x > 11] | Correct list comprehension. | Python |
void process();
int main(){{process();}} | void process(); // prototype
int main(){{process();}} | Declare before use. | C++ |
52index = 10 | index52 = 10 | Variable cannot start with digit. | Python |
function handle(a:string){{return a;}} handle(27); | function handle(a:string){{return a;}} handle('world'); | Pass correct type. | TypeScript |
def bar
puts 'result'
end | def bar
puts 'result'
end | Correct. | Ruby |
println('info') | println("info") | Double quotes. | Scala |
while read line; do echo $line; done < config.json | while read line; do echo $line; done < config.json | Correct. | Shell |
for a in range(25)
print(a) | for a in range(25):
print(a) | Colon after for. | Python |
int x; System.out.println(x); | int x = 0; System.out.println(x); | Initialize variable. | Java |
JOIN products ON items.id = products.name | JOIN products ON items.id = products.name | Correct. | SQL |
let result = 'info' | let result = "info" | Double quotes. | Swift |
<center>test</center> | <div style='text-align:center;'>test</div> | Use CSS. | HTML |
$x = 5; if ($x -eq 5) { Write-Host 'yes' } | $x = 5; if ($x -eq 5) { Write-Host 'yes' } | Correct. | PowerShell |
if x = 40 {{}} | if x == 40 {{}} | Use ==. | Swift |
$items[87] | if ($items.Count -gt 87) {{ $items[87] }} | Check bounds. | PowerShell |
yield result | yield result | Correct yield. | Python |
<a href='https://example.com' target='_blank'> | <a href='https://example.com' target='_blank' rel='noopener'> | Add rel for security. | HTML |
INSERT INTO orders VALUES ('message',50) | INSERT INTO orders (id, email) VALUES ('message',50); | Specify columns. | SQL |
{{'title':'value'}} | {{"title":"value"}} | Use double quotes. | JSON |
cin >> y
cout << y; | cin >> y;
cout << y; | Add semicolon. | C++ |
if x = 35 | if x == 35 | Use ==. | MATLAB |
list[75] | if (list.indices.contains(75)) list[75] | Check index. | Kotlin |
{ "name": "value" } | { "name": "value" } | Correct. | JSON |
let result: number = 'hello'; | let result: string = 'hello'; | Fix type. | TypeScript |
["value", 10] | ["value", 10] | Correct. | JSON |
int c = 'world'; | String c = 'world'; | Type mismatch. | Dart |
int &ref; | int x; int &ref = x; | Reference must be initialized. | C++ |
if (z) console.log('yes') else console.log('no') | if (z) console.log('yes'); else console.log('no'); | Missing semicolon. | JavaScript |
#main {{ color: blue; }} | #main {{ color: blue; }} | Correct. | CSS |
let y = 'test' | let y = "test" | Double quotes. | Swift |
var z int = 'result' | var z string = 'result' | Type mismatch. | Go |
name: result
age: 55 | name: result
age: 55 | Correct. | YAML |
def foo
puts 'output'
end | def foo
puts 'output'
end | Correct. | Ruby |
var x = 5; x = true | var x = 5; x = 10 | Type mismatch. | Kotlin |
<table><tr><td>data<td>test</tr></table> | <table><tr><td>data</td><td>test</td></tr></table> | Close td. | HTML |
while c > 46
c -= 1 | while c > 46:
c -= 1 | Colon missing after while. | Python |
for i in $(ls); do echo $i; done | for i in $(ls); do echo $i; done | Correct. | Shell |
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