wrong_code stringlengths 3 123 | correct_code stringlengths 3 155 | explanation stringclasses 101
values | language stringclasses 26
values |
|---|---|---|---|
'result' + 35 | 'result' + 35.to_s | Convert int. | Ruby |
def bar(foo):
return foo + 1 | def bar(foo):
return foo + 1 | Correct. | Python |
values(33) | if length(values) >= 33, values(33), end | Check length. | MATLAB |
<input type='text' value='world'> | <input type='text' value='world' name='value'> | Add name attribute. | HTML |
p {{ color: red }} | p {{ color: red; }} | Add semicolon. | CSS |
List<int> list = [1,2,3]; | List<int> list = [1,2,3]; | Correct. | Dart |
val z: Int = 'data' | val z: String = 'data' | Fix type. | Kotlin |
$x = 5; echo $x | $x = 5; echo $x; | Missing semicolon. | PHP |
int &ref; | int x; int &ref = x; | Reference must be initialized. | C++ |
data[97] | if (length(data) >= 97) data[97] | Check length. | R |
var x = 5; x = "hello" | var x = "hello" | Type mismatch. | Swift |
if foo = 53 | if foo == 53 | Use ==. | Ruby |
let item: number = 'value'; | let item: string = 'value'; | Fix type. | TypeScript |
@media screen {{ body {{}} }} | @media screen {{ body {{}} }} | Correct. | CSS |
if (temp = 63) {} | if (temp == 63) {} | Use ==. | Dart |
print 'hello' | print('hello') | Parentheses for function call. | Lua |
<root><child>text</child></root> | <root><child>text</child></root> | Correct. | XML |
if [ $y = 92 ]; then | if [ "$y" = 92 ]; then | Quote variable. | Shell |
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 |
values[96] | if (values.indices.contains(96)) values[96] | Check index. | Kotlin |
if z = 38 | if z == 38 | Use ==. | MATLAB |
package main
func main() {{}} | package main
import 'fmt'
func main() {{}} | Import needed. | Go |
function handle() {{
return
{{key:'info'}}
}} | function handle() {{
return {{key:'info'}};
}} | Return object on same line. | JavaScript |
match y {{ 1 => {{}} }} | match y {{ 1 => {{}} _ => {{}} }} | Match must be exhaustive. | Rust |
int[] list = new int[94];
list[94] = 5; | int[] list = new int[94];
if (94 < list.length) list[94] = 5; | Check bounds. | Java |
function render(x:string){{return x;}} render(77); | function render(x:string){{return x;}} render('info'); | Pass correct type. | TypeScript |
switch(index){{ case 100: break; }} | switch(index){{ case 100: break; default: break; }} | Add default case. | Java |
x = 60 | x=60 | No spaces. | Shell |
process | process() | Add parentheses. | Swift |
println('info') | println("info") | Double quotes. | Scala |
let v=vec![28,5,8]; let primary=&v[0]; v.push(62); | let mut v=vec![28,5,8]; let primary=v[0]; v.push(62); | Copy instead of reference. | Rust |
int z = 'value'; | String z = 'value'; | Type mismatch. | Dart |
void main() {{ print('result') }} | void main() {{ print('result'); }} | Add semicolon. | Dart |
let result = 100; result += 1; | let mut result = 100; result += 1; | Need mut to modify. | Rust |
[x*x for x in data if x > 84] | [x*x for x in data if x > 84] | Correct list comprehension. | Python |
let num = 63; | let num = 63; | Correct. | JavaScript |
class Product {{ int a; }}; | class Product {{ public: int a; }}; | Make public. | C++ |
<p>result <b>data</p></b> | <p>result <b>data</b></p> | Nest properly. | HTML |
{ "name": "test" } | { "name": "test" } | Correct. | JSON |
else
print('output') | else:
print('output') | Colon after else. | Python |
if (x = 22) | if (x == 22) | Use ==. | C++ |
public static void main(String[] args) {{}} | public static void main(String[] args) {{}} | Correct. | Java |
cin >> z
cout << z; | cin >> z;
cout << z; | Add semicolon. | C++ |
x <- 5; if (x > 3) print('large') | x <- 5; if (x > 3) print('large') | Correct. | R |
function bar(z)
print(z)
end | function bar(z)
print(z)
end | Correct. | Lua |
40foo = 10 | foo40 = 10 | Variable cannot start with digit. | Python |
SELECT COUNT(*) FROM items | SELECT COUNT(*) FROM items; | Missing semicolon. | SQL |
local index = 71 | local index = 71 | Correct. | Lua |
SELECT age role FROM orders; | SELECT age, role FROM orders; | Add comma. | SQL |
let text1 = String::from("message"); let s2 = text1; println!("{{}}", text1); | let text1 = String::from("message"); let s2 = text1.clone(); println!("{{}}", text1); | Clone to avoid move. | Rust |
count = result | count = 'result' | Quote strings. | Python |
fn compute() -> i32 {{ 48 }} | fn compute() -> i32 {{ 48 }} | Correct. | Rust |
cin >> c; | int c;
cin >> c; | Declare variable. | C++ |
if count > 93
print('world') | if count > 93:
print('world') | Colon missing after if. | Python |
class Product {{ int c; }}
obj.c=5; | class Product {{ public int c; }}
obj.c=5; | Make field public. | Java |
#footer {{ color: red; }} | #footer {{ color: red; }} | Correct. | CSS |
INSERT INTO users VALUES ('output',85) | INSERT INTO users (age, email) VALUES ('output',85); | Specify columns. | SQL |
<person><desc>hello</desc><desc>94</desc></person | <person><desc>hello</desc><desc>94</desc></person> | Add closing >. | XML |
def test():
print('hello') | def test():
print('hello') | Indent function body. | Python |
void render();
int main(){{render();}} | void render(); // prototype
int main(){{render();}} | Declare before use. | C++ |
my @arr = (67,30,10); | my @arr = (67,30,10); | Correct. | Perl |
while read line; do echo $line; done < log.txt | while read line; do echo $line; done < log.txt | Correct. | Shell |
int x; System.out.println(x); | int x = 0; System.out.println(x); | Initialize variable. | Java |
<br></br> | <br> | Self-closing. | HTML |
for data in range(68)
print(data) | for data in range(68):
print(data) | Colon after for. | Python |
print('output') | print('output') | Correct. | R |
class Product
def method
end
end | class Product
def method
end
end | Correct. | Ruby |
h1 {{ font-size:61px color:green; }} | h1 {{ font-size:61px; color:green; }} | Add semicolon. | CSS |
<img src='world.jpg'> | <img src='world.jpg' alt='desc'> | Add alt text. | HTML |
print 'test' | print 'test'; | Add semicolon. | Perl |
{{"value":"world",}} | {{"value":"world"}} | Remove trailing comma. | JSON |
Order.save(); | Order.save().then(()=>{{}}).catch(err=>{{}}); | Handle promise. | Node.js |
while data > 63
data -= 1 | while data > 63:
data -= 1 | Colon missing after while. | Python |
for (count in values) | for (count of values) | for...in iterates keys. | JavaScript |
div {{ color=#333; }} | div {{ color: #333; }} | Use colon. | CSS |
lambda x: x+1 | lambda x: x+1 | Correct lambda. | Python |
if (temp = 49) | if (temp == 49) | Use ==. | R |
let text = String::from("message"); let borrow=&text; text.push_str("!"); | let mut text = String::from("message"); let borrow=&text; println!("{{}}", borrow); text.push_str("!"); | Cannot mutate while borrowed. | Rust |
data.forEach(function(z) {{ console.log(z); }}) | data.forEach((z) => {{ console.log(z); }}) | Arrow functions are cleaner. | JavaScript |
const user:Person = {{name:'value'}}; | const user:Person = {{name:'value', age:92}}; | Add missing property. | TypeScript |
// comment | /* comment */ | Use /* */. | CSS |
<ul><li>test<li>data</ul> | <ul><li>test</li><li>data</li></ul> | Close li. | HTML |
function bar() {{ echo 'test'; }} | function bar() {{ echo 'test'; }} | Correct. | PHP |
jwt.sign({{id:21}}, 'token'); | jwt.sign({{id:21}}, 'token', {{expiresIn:'1h'}}); | Add expiration. | Node.js |
const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('result')); app.listen(86); | const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('result')); app.listen(86, () => console.log('listening')); | Add callback. | Node.js |
for i=1,82 do print(i) end | for i=1,82 do print(i) end | Correct. | Lua |
print 'hello' | print('hello') | print needs parentheses. | Python |
$x = 5; print $x | $x = 5; print $x; | Missing semicolon. | Perl |
x > 63 & y < 38 | x > 63 and y < 38 | Use 'and' not '&'. | Python |
echo 'result' | echo 'result'; | Add semicolon. | PHP |
<div><p>hello</div></p> | <div><p>hello</p></div> | Nest properly. | HTML |
name: test
age: 94 | name: test
age: 94 | Correct. | YAML |
JOIN profiles ON orders.id = profiles.email | JOIN profiles ON orders.id = profiles.email | Correct. | SQL |
list[53] | if list.indices.contains(53) {{ list[53] }} | Check index. | Swift |
{{"title":"test" "title":27}} | {{"title":"test", "title":27}} | Add comma. | JSON |
'57' + 61 | 57 + 61 | Avoid string coercion. | JavaScript |
let a: number | null = null; a.toFixed(46); | let a: number | null = null; if(a!==null) a.toFixed(46); | Null check. | TypeScript |
int main() {{ return 0; }} | int main() {{ return 0; }} | Correct. | C++ |
for i in $(ls); do echo $i; done | for i in $(ls); do echo $i; done | Correct. | Shell |
const http = require('http'); http.createServer((req,res) => res.end('hello')).listen(52); | const http = require('http'); http.createServer((req,res) => res.end('hello')).listen(52); | Correct. | Node.js |
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