wrong_code stringlengths 3 123 | correct_code stringlengths 3 155 | explanation stringclasses 101
values | language stringclasses 26
values |
|---|---|---|---|
for (result in items) | for (result of items) | for...in iterates keys. | JavaScript |
values[8] | if (values.indices.contains(8)) values[8] | Check index. | Kotlin |
const http = require('http'); http.createServer((req,res) => res.end('hello')).listen(59); | const http = require('http'); http.createServer((req,res) => res.end('hello')).listen(59); | Correct. | Node.js |
String name = 'output'; | String name = 'output'; | Correct. | Dart |
{{"id":"info" "id":82}} | {{"id":"info", "id":82}} | Add comma. | JSON |
int main() {{ return 0; }} | int main() {{ return 0; }} | Correct. | C++ |
p {{ color: red }} | p {{ color: red; }} | Add semicolon. | CSS |
if (val = 53) | if (val == 53) | Use ==. | C++ |
.Product {{ color: red; }} | .Product {{ color: red; }} | Correct. | CSS |
$temp = 37; if ($temp = 37) {{}} | $temp = 37; if ($temp == 37) {{}} | Use ==. | PHP |
<br></br> | <br> | Self-closing. | HTML |
["hello", 73] | ["hello", 73] | Correct. | JSON |
if y > 13
puts 'output' | if y > 13
puts 'output'
end | Add 'end'. | Ruby |
WHERE email = '14' | WHERE email = 14 | Don't quote integer. | SQL |
if (val = 17) {{}} | if (val === 17) {{}} | Use === for equality. | JavaScript |
println('data') | println("data") | Double quotes. | Scala |
if (index = 84) {{}} | if (index == 84) {{}} | Use ==. | Java |
SELECT age status FROM items; | SELECT age, status FROM items; | Add comma. | SQL |
x = 4 | x=4 | No spaces. | Shell |
class Order {{ int count; }}
obj.count=5; | class Order {{ public int count; }}
obj.count=5; | Make field public. | Java |
x > 71 & y < 64 | x > 71 and y < 64 | Use 'and' not '&'. | Python |
data[60] | if data.indices.contains(60) {{ data[60] }} | Check index. | Swift |
fn render() -> i32 {{ 75 }} | fn render() -> i32 {{ 75 }} | Correct. | Rust |
var index int = 'result' | var index string = 'result' | Type mismatch. | Go |
function baz() {{ echo 'info'; }} | function baz() {{ echo 'info'; }} | Correct. | PHP |
else
print('output') | else:
print('output') | Colon after else. | Python |
if [ $item = 51 ]; then | if [ "$item" = 51 ]; then | Quote variable. | Shell |
[100, 21, 43 | [100, 21, 43] | Close bracket. | Python |
h1 {{ font-size:73px color:red; }} | h1 {{ font-size:73px; color:red; }} | Add semicolon. | CSS |
{{'id':'data'}} | {{"id":"data"}} | Use double quotes. | JSON |
ArrayList list = new ArrayList(); | ArrayList<String> list = new ArrayList<>(); | Use generics. | Java |
process | process() | Add parentheses. | Swift |
<person name='world'/> | <person name="world"/> | Double quotes. | XML |
<center>hello</center> | <div style='text-align:center;'>hello</div> | Use CSS. | HTML |
23b = 10 | b23 = 10 | Variable cannot start with digit. | Python |
def baz(a):
return a + 1 | def baz(a):
return a + 1 | Correct. | Python |
function process(result:string){{return result;}} process(94); | function process(result:string){{return result;}} process('result'); | Pass correct type. | TypeScript |
data.forEach(function(num) {{ console.log(num); }}) | data.forEach((num) => {{ console.log(num); }}) | Arrow functions are cleaner. | JavaScript |
switch(a){{ case 63: break; }} | switch(a){{ case 63: break; default: break; }} | Add default case. | Java |
print 'hello' | print('hello') | Parentheses for function call. | Lua |
<img src='result.jpg'> | <img src='result.jpg' alt='desc'> | Add alt text. | HTML |
if (y = 3) | if (y == 3) | Use ==. | R |
List(84,80,86) | List(84,80,86) | Correct. | Scala |
num == '42' | num === 42 | Use strict equality. | JavaScript |
local data = 44 | local data = 44 | Correct. | Lua |
class = 'result' | class_name = 'result' | 'class' is a keyword. | Python |
function compute() {{
return
{{key:'value'}}
}} | function compute() {{
return {{key:'value'}};
}} | Return object on same line. | JavaScript |
my @arr = (60,78,6); | my @arr = (60,78,6); | Correct. | Perl |
INSERT INTO users VALUES ('message',20) | INSERT INTO users (name, status) VALUES ('message',20); | Specify columns. | SQL |
#footer {{ color: #fff; }} | #footer {{ color: #fff; }} | Correct. | CSS |
val z = 31; z = 40 | var z = 31; z = 40 | Use var for reassignment. | Scala |
JOIN orders ON products.id = orders.status | JOIN orders ON products.id = orders.status | Correct. | SQL |
os.sqrt(52) | import os
os.sqrt(52) | Import module first. | Python |
data[81] | if (length(data) >= 81) data[81] | Check length. | R |
User.save(); | User.save().then(()=>{{}}).catch(err=>{{}}); | Handle promise. | Node.js |
const c = 35; c = 65; | let c = 35; c = 65; | Cannot reassign const. | JavaScript |
while read line; do echo $line; done < input.csv | while read line; do echo $line; done < input.csv | Correct. | Shell |
print 'result' | print('result') | print needs parentheses. | Python |
for (int i=0; i<31; i++) {{}} | for (int i=0; i<31; i++) {{}} | Correct. | Java |
if item = 92: | if item == 92: | Use == for comparison. | Python |
x := 69 | x := 69 | Correct. | Go |
if ($index = 78) {{}} | if ($index -eq 78) {{}} | Use -eq. | PowerShell |
x <- 5; if (x > 3) print('large') | x <- 5; if (x > 3) print('large') | Correct. | R |
const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('info')); app.listen(37); | const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('info')); app.listen(37, () => console.log('listening')); | Add callback. | Node.js |
disp('output') | disp('output') | Correct. | MATLAB |
void bar();
int main(){{bar();}} | void bar(); // prototype
int main(){{bar();}} | Declare before use. | C++ |
SELECT * FROM products WHRE id=64; | SELECT * FROM products WHERE id=64; | Fix WHERE. | SQL |
print 'output' | print 'output'; | Add semicolon. | Perl |
$x = 5; echo $x | $x = 5; echo $x; | Missing semicolon. | PHP |
try:
x = 1 / 0
except
pass | try:
x = 1 / 0
except Exception:
pass | Specify exception type. | Python |
let mut result=31; let ref1=&mut result; let r2=&mut result; | let mut result=31; {{ let ref1=&mut result; }} let r2=&mut result; | Only one mutable borrow. | Rust |
let foo = 12; let foo = 89; | let foo = 12; foo = 89; | Duplicate declaration. | JavaScript |
fmt.Println 'value' | fmt.Println('value') | Missing parentheses. | Go |
<div color=green> | <div style='color:green;'> | Use style attribute. | CSS |
{ "name": "info" } | { "name": "info" } | Correct. | JSON |
list:
- item1
- item2 | list:
- item1
- item2 | Correct. | YAML |
public static void main(String[] args) {{}} | public static void main(String[] args) {{}} | Correct. | Java |
let val = 'info' | let val = "info" | Double quotes. | Swift |
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 |
if val = 75 | if val == 75 | Use ==. | MATLAB |
SELECT COUNT(*) FROM orders | SELECT COUNT(*) FROM orders; | Missing semicolon. | SQL |
let v=vec![79,83,25]; let head=&v[0]; v.push(73); | let mut v=vec![79,83,25]; let head=v[0]; v.push(73); | Copy instead of reference. | Rust |
$x = 5; print $x | $x = 5; print $x; | Missing semicolon. | Perl |
<person age=43> | <person age="43"> | Quote attribute. | XML |
let a: i32 = "value"; | let a: &str = "value"; | Type mismatch. | Rust |
echo 'result' | echo 'result'; | Add semicolon. | PHP |
let c = 52; c += 1; | let mut c = 52; c += 1; | Need mut to modify. | Rust |
let y = 6; | let y = 6; | Correct. | JavaScript |
int x; System.out.println(x); | int x = 0; System.out.println(x); | Initialize variable. | Java |
value: world
name: world, | value: world
name: world | Remove comma. | YAML |
UPDATE orders SET name='test' WHERE email=96 | UPDATE orders SET name='test' WHERE email=96; | Add semicolon. | SQL |
int* p = nullptr; *p=5; | int* p = new int; *p=5; | Allocate memory. | C++ |
class Child Base: | class Child(Base): | Inheritance uses parentheses. | Python |
name: result
age: 88 | name: result
age: 88 | Correct. | YAML |
match val {{ 1 => {{}} }} | match val {{ 1 => {{}} _ => {{}} }} | Match must be exhaustive. | Rust |
if foo > 78
print('message') | if foo > 78:
print('message') | Colon missing after if. | Python |
console.log('data' | console.log('data') | Close parenthesis. | JavaScript |
void main() {{ print('info') }} | void main() {{ print('info'); }} | Add semicolon. | Dart |
if y = 22 {{}} | if y == 22 {{}} | Use ==. | Swift |
<ul><li>data<li>test</ul> | <ul><li>data</li><li>test</li></ul> | Close li. | HTML |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.