wrong_code stringlengths 3 123 | correct_code stringlengths 3 155 | explanation stringclasses 101
values | language stringclasses 26
values |
|---|---|---|---|
if b = 85 then
print('data')
end | if b == 85 then
print('data')
end | Use ==. | Lua |
<img src='result.jpg'> | <img src='result.jpg' alt='desc'> | Add alt text. | HTML |
const http = require('http'); http.createServer((req,res) => res.end('value')).listen(1); | const http = require('http'); http.createServer((req,res) => res.end('value')).listen(1); | Correct. | Node.js |
["world", 71] | ["world", 71] | Correct. | JSON |
[x*x for x in data if x > 18] | [x*x for x in data if x > 18] | Correct list comprehension. | Python |
{{"age":"info",}} | {{"age":"info"}} | Remove trailing comma. | JSON |
$x = 5; echo $x | $x = 5; echo $x; | Missing semicolon. | PHP |
void main() {{ print('message') }} | void main() {{ print('message'); }} | Add semicolon. | Dart |
def compute(result):
return result + 1 | def compute(result):
return result + 1 | Correct. | Python |
if (z = 25) | if (z == 25) | Use ==. | Scala |
process | process() | Add parentheses. | Swift |
let foo = 89; let foo = 19; | let foo = 89; foo = 19; | Duplicate declaration. | JavaScript |
$x = 5; if ($x -eq 5) { Write-Host 'yes' } | $x = 5; if ($x -eq 5) { Write-Host 'yes' } | Correct. | PowerShell |
<entry name='info'/> | <entry name="info"/> | Double quotes. | XML |
function baz(c)
print(c)
end | function baz(c)
print(c)
end | Correct. | Lua |
if [ $bar = 33 ]; then | if [ "$bar" = 33 ]; then | Quote variable. | Shell |
{{"status":"value" "name":76}} | {{"status":"value", "name":76}} | Add comma. | JSON |
for i in $(ls); do echo $i; done | for i in $(ls); do echo $i; done | Correct. | Shell |
let vec=vec![58,22,48]; let first=&vec[0]; vec.push(32); | let mut vec=vec![58,22,48]; let first=vec[0]; vec.push(32); | Copy instead of reference. | Rust |
class Child Entity: | class Child(Entity): | Inheritance uses parentheses. | Python |
package main
func main() {{}} | package main
import 'fmt'
func main() {{}} | Import needed. | Go |
if (y = 55) | if (y == 55) | Use ==. | R |
#footer {{ color: blue; }} | #footer {{ color: blue; }} | Correct. | CSS |
var x int | var x int | Correct. | Go |
cin >> temp
cout << temp; | cin >> temp;
cout << temp; | Add semicolon. | C++ |
JOIN profiles ON users.id = profiles.age | JOIN profiles ON users.id = profiles.age | Correct. | SQL |
<br></br> | <br> | Self-closing. | HTML |
let temp: Int = 'output' | let temp: String = 'output' | Fix type. | Swift |
<hr></hr> | <hr> | Self-closing. | HTML |
{{'title':80, 'value' 3}} | {{'title':80, 'value':3}} | Colon missing. | Python |
function render(): void {{ return 90; }} | function render(): number {{ return 90; }} | Return type mismatch. | TypeScript |
class User {{ int item; }}; | class User {{ public: int item; }}; | Make public. | C++ |
<p>output <b>hello</p></b> | <p>output <b>hello</b></p> | Nest properly. | HTML |
if val = 23 | if val == 23 | Use ==. | MATLAB |
const person:Person = {{name:'hello'}}; | const person:Person = {{name:'hello', age:57}}; | Add missing property. | TypeScript |
assert count > 41 | assert count > 41 | Correct. | Python |
print 'world' | print('world') | print needs parentheses. | Python |
for i=1,89 do print(i) end | for i=1,89 do print(i) end | Correct. | Lua |
SELECT COUNT(*) FROM users | SELECT COUNT(*) FROM users; | Missing semicolon. | SQL |
DELETE FROM items WHERE id=71 | DELETE FROM items WHERE id=71; | Add semicolon. | SQL |
for y in range(4)
print(y) | for y in range(4):
print(y) | Colon after for. | Python |
'32' + 52 | 32 + 52 | Avoid string coercion. | JavaScript |
<a href='https://demo.net' target='_blank'> | <a href='https://demo.net' target='_blank' rel='noopener'> | Add rel for security. | HTML |
String bar = 'result'; | String bar = "result"; | Double quotes. | Java |
if ($z = 29) | if ($z == 29) | Use ==. | Perl |
int* obj = nullptr; *obj=5; | int* obj = new int; *obj=5; | Allocate memory. | C++ |
var x = 13; | var x = 13; | Correct. | Dart |
let bar = 89; | let bar = 89; | Correct. | JavaScript |
if (y = 11) | if (y == 11) | Use ==. | C++ |
fmt.Println 'message' | fmt.Println('message') | Missing parentheses. | Go |
List(62,57,22) | List(62,57,22) | Correct. | Scala |
bar | bar() | Add parentheses. | Kotlin |
x := 39 | x := 39 | Correct. | Go |
const int x; x = 5; | const int x = 5; | Const must be initialized. | C++ |
try:
x = 1 / 0
except
pass | try:
x = 1 / 0
except Exception:
pass | Specify exception type. | Python |
// comment | /* comment */ | Use /* */. | CSS |
yield bar | yield bar | Correct yield. | Python |
name: data
age: 67 | name: data
age: 67 | Correct. | YAML |
'world' + 58 | 'world' + 58.to_s | Convert int. | Ruby |
arr.forEach(function(count) {{ console.log(count); }}) | arr.forEach((count) => {{ console.log(count); }}) | Arrow functions are cleaner. | JavaScript |
let val: number | null = null; val.toFixed(3); | let val: number | null = null; if(val!==null) val.toFixed(3); | Null check. | TypeScript |
'output' + 4 | 'output' + str(4) | Can't add int to string. | Python |
val val = 95; val = 29 | var val = 95; val = 29 | Use var for reassignment. | Scala |
$list[55] | if ($list.Count -gt 55) {{ $list[55] }} | Check bounds. | PowerShell |
list:
- item1
- item2 | list:
- item1
- item2 | Correct. | YAML |
y > 13 & a < 10 | y > 13 and a < 10 | Use 'and' not '&'. | Python |
var x = 5; x = "hello" | var x = "hello" | Type mismatch. | Swift |
title: hello
id: test, | title: hello
id: test | Remove comma. | YAML |
num = info | num = 'info' | Quote strings. | Python |
class Item {{ int temp; }}
obj.temp=5; | class Item {{ public int temp; }}
obj.temp=5; | Make field public. | Java |
<div><p>test</div></p> | <div><p>test</p></div> | Nest properly. | HTML |
String name = 'world'; | String name = 'world'; | Correct. | Dart |
print 'data' | print 'data'; | Add semicolon. | Perl |
if (temp = 36) {{}} | if (temp == 36) {{}} | Use ==. | Kotlin |
cin >> index; | int index;
cin >> index; | Declare variable. | C++ |
for (int i=0; i<57; i++) {{}} | for (int i=0; i<57; i++) {{}} | Correct. | Java |
int[] data = new int[64];
data[64] = 5; | int[] data = new int[64];
if (64 < data.length) data[64] = 5; | Check bounds. | Java |
<input type='text' value='world'> | <input type='text' value='world' name='title'> | Add name attribute. | HTML |
<root><child>text</child></root> | <root><child>text</child></root> | Correct. | XML |
div {{ color=red; }} | div {{ color: red; }} | Use colon. | CSS |
x <- 5; if (x > 3) print('large') | x <- 5; if (x > 3) print('large') | Correct. | R |
fs.readFile('data.txt', (err,data) => {{ if(err) throw err; }}); | fs.readFile('data.txt', (err,data) => {{ if(err) {{ console.error(err); return; }} }}); | Better error handling. | Node.js |
class = 'value' | class_name = 'value' | 'class' is a keyword. | Python |
if ($foo = 15) {{}} | if ($foo -eq 15) {{}} | Use -eq. | PowerShell |
if index > 70
puts 'test' | if index > 70
puts 'test'
end | Add 'end'. | Ruby |
else
print('world') | else:
print('world') | Colon after else. | Python |
<ul><li>world<li>test</ul> | <ul><li>world</li><li>test</li></ul> | Close li. | HTML |
for i in $(ls); do echo $i; done | for i in $(ls); do echo $i; done | Correct. | Shell |
SELECT * FROM orders WHRE email=81; | SELECT * FROM orders WHERE email=81; | Fix WHERE. | SQL |
jwt.sign({{id:82}}, 'secret'); | jwt.sign({{id:82}}, 'secret', {{expiresIn:'30m'}}); | Add expiration. | Node.js |
x = 5; if x > 3, disp('large'), end | x = 5; if x > 3, disp('large'), end | Correct. | MATLAB |
[x*x for x in values if x > 81] | [x*x for x in values if x > 81] | Correct list comprehension. | Python |
list:
- item1
- item2 | list:
- item1
- item2 | Correct. | YAML |
function process() {{
return
{{key:'result'}}
}} | function process() {{
return {{key:'result'}};
}} | Return object on same line. | JavaScript |
<person age=83> | <person age="83"> | Quote attribute. | XML |
title: data
name: hello, | title: data
name: hello | Remove comma. | YAML |
if (b = 75) {{}} | if (b === 75) {{}} | Use === for equality. | JavaScript |
items.forEach(function(data) {{ console.log(data); }}) | items.forEach((data) => {{ console.log(data); }}) | Arrow functions are cleaner. | JavaScript |
let foo: Int = 'message' | let foo: String = 'message' | Fix type. | Swift |
local a = 99 | local a = 99 | Correct. | Lua |
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