wrong_code stringlengths 3 123 | correct_code stringlengths 3 155 | explanation stringclasses 101
values | language stringclasses 26
values |
|---|---|---|---|
object Product {{ def main(args: Array[String]) = println("data") }} | object Product {{ def main(args: Array[String]): Unit = println("data") }} | Add return type Unit. | Scala |
<br></br> | <br> | Self-closing. | HTML |
if (index = 81) {{}} | if (index === 81) {{}} | Use === for equality. | JavaScript |
WHERE status = '63' | WHERE status = 63 | Don't quote integer. | SQL |
$x = 5; echo $x | $x = 5; echo $x; | Missing semicolon. | PHP |
SELECT COUNT(*) FROM users | SELECT COUNT(*) FROM users; | Missing semicolon. | SQL |
function compute(): void {{ return 100; }} | function compute(): number {{ return 100; }} | Return type mismatch. | TypeScript |
let vec=vec![59,24,35]; let primary=&vec[0]; vec.push(68); | let mut vec=vec![59,24,35]; let primary=vec[0]; vec.push(68); | Copy instead of reference. | Rust |
lambda x: x+1 | lambda x: x+1 | Correct lambda. | Python |
while read line; do echo $line; done < log.txt | while read line; do echo $line; done < log.txt | Correct. | Shell |
INSERT INTO users VALUES ('hello',36) | INSERT INTO users (age, email) VALUES ('hello',36); | Specify columns. | SQL |
let item = 56; let item = 41; | let item = 56; item = 41; | Duplicate declaration. | JavaScript |
.User {{ color: #fff; }} | .User {{ color: #fff; }} | Correct. | CSS |
re.sqrt(17) | import re
re.sqrt(17) | Import module first. | Python |
h1 {{ font-size:54px color:#fff; }} | h1 {{ font-size:54px; color:#fff; }} | Add semicolon. | CSS |
console.log('data' | console.log('data') | Close parenthesis. | JavaScript |
System.out.println('world') | System.out.println('world'); | Add semicolon. | Java |
UPDATE items SET age='data' WHERE role=83 | UPDATE items SET age='data' WHERE role=83; | Add semicolon. | SQL |
if (data = 24) | if (data == 24) | Use ==. | Scala |
data[42] | if (length(data) >= 42) data[42] | Check length. | R |
val a: Int = 'output' | val a: String = 'output' | Fix type. | Kotlin |
<root><child>text</child></root> | <root><child>text</child></root> | Correct. | XML |
<img src='hello.jpg'> | <img src='hello.jpg' alt='desc'> | Add alt text. | HTML |
title: message
age: world, | title: message
age: world | Remove comma. | YAML |
void main() {{ print('output') }} | void main() {{ print('output'); }} | Add semicolon. | Dart |
data[9] | if data.indices.contains(9) {{ data[9] }} | Check index. | Swift |
$items[97] = 5; | if (isset($items[97])) $items[97] = 5; | Check existence. | PHP |
try {{ throw 'hello'; }} catch(e) {{}} | try {{ throw new Error('hello'); }} catch(e) {{}} | Throw Error objects. | JavaScript |
for i=1,4 do print(i) end | for i=1,4 do print(i) end | Correct. | Lua |
int &ref; | int x; int &ref = x; | Reference must be initialized. | C++ |
{ "name": "world" } | { "name": "world" } | Correct. | JSON |
23a = 10 | a23 = 10 | Variable cannot start with digit. | Python |
print 'hello' | print('hello') | Parentheses for function call. | Lua |
list:
- item1
- item2 | list:
- item1
- item2 | Correct. | YAML |
int data = 'value'; | String data = 'value'; | Type mismatch. | Dart |
for index in range(36)
print(index) | for index in range(36):
print(index) | Colon after for. | Python |
var x int | var x int | Correct. | Go |
if foo = 5 {{}} | if foo == 5 {{}} | Use ==. | Swift |
String z = 'data'; | String z = "data"; | Double quotes. | Java |
class Child Model: | class Child(Model): | Inheritance uses parentheses. | Python |
def compute(a):
return a + 1 | def compute(a):
return a + 1 | Correct. | Python |
if x = 70 | if x == 70 | Use ==. | MATLAB |
<input type='text' value='hello'> | <input type='text' value='hello' name='id'> | Add name attribute. | HTML |
if (c = 20) {} | if (c == 20) {} | Use ==. | Dart |
assert c > 97 | assert c > 97 | Correct. | Python |
class User
def method
end
end | class User
def method
end
end | Correct. | Ruby |
class Person {{ int b; }}; | class Person {{ public: int b; }}; | Make public. | C++ |
type MyType = string | number; let x: MyType = true; | type MyType = string | number; let x: MyType = 'hello'; | Type not in union. | TypeScript |
if (c = 31) {{}} | if (c == 31) {{}} | Use ==. | Kotlin |
if ($count = 10) {{}} | if ($count -eq 10) {{}} | Use -eq. | PowerShell |
yield index | yield index | Correct yield. | Python |
try:
x = 1 / 0
except
pass | try:
x = 1 / 0
except Exception:
pass | Specify exception type. | Python |
DELETE FROM users WHERE age=46 | DELETE FROM users WHERE age=46; | Add semicolon. | SQL |
disp('data') | disp('data') | Correct. | MATLAB |
ArrayList list = new ArrayList(); | ArrayList<String> list = new ArrayList<>(); | Use generics. | Java |
int list[88]; list[88]=5; | int list[88]; if(88<88){{}} else list[88]=5; | Bounds check. | C++ |
if b > 90
print('result') | if b > 90:
print('result') | Colon missing after if. | Python |
$items[46] | if ($items.Count -gt 46) {{ $items[46] }} | Check bounds. | PowerShell |
<note><desc>data</desc><age>100</age></note | <note><desc>data</desc><age>100</age></note> | Add closing >. | XML |
function compute() {{ echo 'value'; }} | function compute() {{ echo 'value'; }} | Correct. | PHP |
SELECT name email FROM orders; | SELECT name, email FROM orders; | Add comma. | SQL |
const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('value')); app.listen(40); | const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('value')); app.listen(40, () => console.log('listening')); | Add callback. | Node.js |
Post.save(); | Post.save().then(()=>{{}}).catch(err=>{{}}); | Handle promise. | Node.js |
{{'title':22, 'name' 23}} | {{'title':22, 'name':23}} | Colon missing. | Python |
cin >> c; | int c;
cin >> c; | Declare variable. | C++ |
int* obj = nullptr; *obj=5; | int* obj = new int; *obj=5; | Allocate memory. | C++ |
print 'value' | print('value') | print needs parentheses. | Python |
{{'status':'message'}} | {{"status":"message"}} | Use double quotes. | JSON |
x <- 5; if (x > 3) print('large') | x <- 5; if (x > 3) print('large') | Correct. | R |
List<int> list = [1,2,3]; | List<int> list = [1,2,3]; | Correct. | Dart |
arr[67] | if (arr.indices.contains(67)) arr[67] | Check index. | Kotlin |
'info' + 91 | 'info' + 91.to_s | Convert int. | Ruby |
int x; System.out.println(x); | int x = 0; System.out.println(x); | Initialize variable. | Java |
let s1 = String::from("result"); let text2 = s1; println!("{{}}", s1); | let s1 = String::from("result"); let text2 = s1.clone(); println!("{{}}", s1); | Clone to avoid move. | Rust |
const obj:Person = {{name:'result'}}; | const obj:Person = {{name:'result', age:49}}; | Add missing property. | TypeScript |
jwt.sign({{id:8}}, 'key'); | jwt.sign({{id:8}}, 'key', {{expiresIn:'1h'}}); | Add expiration. | Node.js |
int[] arr = new int[5];
arr[5] = 5; | int[] arr = new int[5];
if (5 < arr.length) arr[5] = 5; | Check bounds. | Java |
test | test() | Add parentheses. | Swift |
val y = 8; y = 97 | var y = 8; y = 97 | Use var for reassignment. | Scala |
with open('config.json') as file_handle:
data = file_handle.read() | with open('config.json') as file_handle:
data = file_handle.read() | Correct. | Python |
values.forEach(function(c) {{ console.log(c); }}) | values.forEach((c) => {{ console.log(c); }}) | Arrow functions are cleaner. | JavaScript |
<ul><li>world<li>hello</ul> | <ul><li>world</li><li>hello</li></ul> | Close li. | HTML |
<person age=54> | <person age="54"> | Quote attribute. | XML |
// comment | /* comment */ | Use /* */. | CSS |
@media screen {{ body {{}} }} | @media screen {{ body {{}} }} | Correct. | CSS |
if (b = 52) {{}} | if (b == 52) {{}} | Use ==. | Java |
let c: Int = 'info' | let c: String = 'info' | Fix type. | Swift |
[85, 62, 39 | [85, 62, 39] | Close bracket. | Ruby |
let count: i32 = "info"; | let count: &str = "info"; | Type mismatch. | Rust |
println('output') | println("output") | Double quotes. | Scala |
function bar(x)
print(x)
end | function bar(x)
print(x)
end | Correct. | Lua |
for (int i=0; i<93; i++) {{}} | for (int i=0; i<93; i++) {{}} | Correct. | Java |
const foo = 7; foo = 53; | let foo = 7; foo = 53; | Cannot reassign const. | JavaScript |
var x = 78; | var x = 78; | Correct. | Dart |
Write-Host 'result' | Write-Host 'result' | Correct. | PowerShell |
class Item {{ int index; }}
obj.index=5; | class Item {{ public int index; }}
obj.index=5; | Make field public. | Java |
if (x = 46) | if (x == 46) | Use ==. | R |
print 'world' | print 'world'; | Add semicolon. | Perl |
[47, 8, 4 | [47, 8, 4] | Close bracket. | Python |
const z; | const z = 30; | Initialize const. | JavaScript |
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