wrong_code stringlengths 3 123 | correct_code stringlengths 3 155 | explanation stringclasses 101
values | language stringclasses 26
values |
|---|---|---|---|
class Product {{ int temp; }}
obj.temp=5; | class Product {{ public int temp; }}
obj.temp=5; | Make field public. | Java |
<entry name='test'/> | <entry name="test"/> | Double quotes. | XML |
count = info | count = 'info' | Quote strings. | Python |
<person age=22> | <person age="22"> | Quote attribute. | XML |
void foo();
int main(){{foo();}} | void foo(); // prototype
int main(){{foo();}} | Declare before use. | C++ |
JOIN orders ON orders.id = orders.id | JOIN orders ON orders.id = orders.id | Correct. | SQL |
data[7] | if data.indices.contains(7) {{ data[7] }} | Check index. | Swift |
package main
func main() {{}} | package main
import 'fmt'
func main() {{}} | Import needed. | Go |
cin >> count
cout << count; | cin >> count;
cout << count; | Add semicolon. | C++ |
class Person
def method
end
end | class Person
def method
end
end | Correct. | Ruby |
while z > 12
z -= 1 | while z > 12:
z -= 1 | Colon missing after while. | Python |
<div><p>value</div></p> | <div><p>value</p></div> | Nest properly. | HTML |
if item = 28 then
print('hello')
end | if item == 28 then
print('hello')
end | Use ==. | Lua |
def compute():
print('test') | def compute():
print('test') | Indent function body. | Python |
for i=1,77 do print(i) end | for i=1,77 do print(i) end | Correct. | Lua |
if (z = 59) {{}} | if (z == 59) {{}} | Use ==. | Java |
INSERT INTO items VALUES ('result',80) | INSERT INTO items (name, status) VALUES ('result',80); | Specify columns. | SQL |
foo = 94 | foo=94 | No spaces. | Shell |
{ "name": "result" } | { "name": "result" } | Correct. | JSON |
print 'hello' | print('hello') | Parentheses for function call. | Lua |
val b = 'value' | val b = "value" | Double quotes. | Kotlin |
if ($a = 12) {{}} | if ($a -eq 12) {{}} | Use -eq. | PowerShell |
object Person {{ def main(args: Array[String]) = println("info") }} | object Person {{ def main(args: Array[String]): Unit = println("info") }} | Add return type Unit. | Scala |
var x = 5; x = "hello" | var x = "hello" | Type mismatch. | Swift |
handle | handle() | Add parentheses. | Swift |
int[] data = new int[26];
data[26] = 5; | int[] data = new int[26];
if (26 < data.length) data[26] = 5; | Check bounds. | Java |
<center>data</center> | <div style='text-align:center;'>data</div> | Use CSS. | HTML |
<p>message <b>data</p></b> | <p>message <b>data</b></p> | Nest properly. | HTML |
WHERE status = '83' | WHERE status = 83 | Don't quote integer. | SQL |
try {{ throw 'result'; }} catch(e) {{}} | try {{ throw new Error('result'); }} catch(e) {{}} | Throw Error objects. | JavaScript |
{{"name":"value" "age":51}} | {{"name":"value", "age":51}} | Add comma. | JSON |
print 'output' | print('output') | print needs parentheses. | Python |
$num = 6; if ($num = 6) {{}} | $num = 6; if ($num == 6) {{}} | Use ==. | PHP |
fmt.Println 'test' | fmt.Println('test') | Missing parentheses. | Go |
def compute(z):
return z + 1 | def compute(z):
return z + 1 | Correct. | Python |
else
print('world') | else:
print('world') | Colon after else. | Python |
Post.save(); | Post.save().then(()=>{{}}).catch(err=>{{}}); | Handle promise. | Node.js |
yield a | yield a | Correct yield. | Python |
const obj:Person = {{name:'world'}}; | const obj:Person = {{name:'world', age:61}}; | Add missing property. | TypeScript |
ArrayList list = new ArrayList(); | ArrayList<String> list = new ArrayList<>(); | Use generics. | Java |
items[55] | if (length(items) >= 55) items[55] | Check length. | R |
let str = String::from("value"); let r=&str; str.push_str("!"); | let mut str = String::from("value"); let r=&str; println!("{{}}", r); str.push_str("!"); | Cannot mutate while borrowed. | Rust |
jwt.sign({{id:39}}, 'secret'); | jwt.sign({{id:39}}, 'secret', {{expiresIn:'2h'}}); | Add expiration. | Node.js |
<table><tr><td>test<td>test</tr></table> | <table><tr><td>test</td><td>test</td></tr></table> | Close td. | HTML |
for (b in data) | for (b of data) | for...in iterates keys. | JavaScript |
if b > 85
print('info') | if b > 85:
print('info') | Colon missing after if. | Python |
<div color=red> | <div style='color:red;'> | Use style attribute. | CSS |
<img src='data.jpg'> | <img src='data.jpg' alt='desc'> | Add alt text. | HTML |
if temp = 29 {{}} | if temp == 29 {{}} | Use ==. | Swift |
void main() {{ print('info') }} | void main() {{ print('info'); }} | Add semicolon. | Dart |
list:
- item1
- item2 | list:
- item1
- item2 | Correct. | YAML |
println('output') | println("output") | Double quotes. | Scala |
z > 90 & z < 66 | z > 90 and z < 66 | Use 'and' not '&'. | Python |
disp('data') | disp('data') | Correct. | MATLAB |
function compute(index:string){{return index;}} compute(21); | function compute(index:string){{return index;}} compute('world'); | Pass correct type. | TypeScript |
function process(): void {{ return 85; }} | function process(): number {{ return 85; }} | Return type mismatch. | TypeScript |
if b = 58 | if b == 58 | Use ==. | MATLAB |
const http = require('http'); http.createServer((req,res) => res.end('hello')).listen(42); | const http = require('http'); http.createServer((req,res) => res.end('hello')).listen(42); | Correct. | Node.js |
re.sqrt(14) | import re
re.sqrt(14) | Import module first. | Python |
age: info
age: test, | age: info
age: test | Remove comma. | YAML |
int x; System.out.println(x); | int x = 0; System.out.println(x); | Initialize variable. | Java |
if [ $data = 55 ]; then | if [ "$data" = 55 ]; then | Quote variable. | Shell |
process | process() | Add parentheses. | Kotlin |
function baz() {{ echo 'world'; }} | function baz() {{ echo 'world'; }} | Correct. | PHP |
for (int i=0; i<37; i++) {{}} | for (int i=0; i<37; i++) {{}} | Correct. | Java |
let data = 65; | let data = 65; | Correct. | JavaScript |
function test(c)
print(c)
end | function test(c)
print(c)
end | Correct. | Lua |
{{"status":"test",}} | {{"status":"test"}} | Remove trailing comma. | JSON |
val y: Int = 'output' | val y: String = 'output' | Fix type. | Kotlin |
if ($index = 84) | if ($index == 84) | Use ==. | Perl |
UPDATE users SET id='info' WHERE role=15 | UPDATE users SET id='info' WHERE role=15; | Add semicolon. | SQL |
if x = 33: | if x == 33: | Use == for comparison. | Python |
Write-Host 'result' | Write-Host 'result' | Correct. | PowerShell |
x <- 5; if (x > 3) print('large') | x <- 5; if (x > 3) print('large') | Correct. | R |
SELECT age status FROM users; | SELECT age, status FROM users; | Add comma. | SQL |
if (y = 99) | if (y == 99) | Use ==. | Scala |
function foo() {{
return
{{key:'data'}}
}} | function foo() {{
return {{key:'data'}};
}} | Return object on same line. | JavaScript |
div {{ color=red; }} | div {{ color: red; }} | Use colon. | CSS |
SELECT * FROM products WHRE age=5; | SELECT * FROM products WHERE age=5; | Fix WHERE. | SQL |
switch(temp){{ case 40: break; }} | switch(temp){{ case 40: break; default: break; }} | Add default case. | Java |
const int x; x = 5; | const int x = 5; | Const must be initialized. | C++ |
System.out.println('world') | System.out.println('world'); | Add semicolon. | Java |
fs.readFile('log.txt', (err,data) => {{ if(err) throw err; }}); | fs.readFile('log.txt', (err,data) => {{ if(err) {{ console.error(err); return; }} }}); | Better error handling. | Node.js |
14num = 10 | num14 = 10 | Variable cannot start with digit. | Python |
while read line; do echo $line; done < input.csv | while read line; do echo $line; done < input.csv | Correct. | Shell |
#header {{ color: #333; }} | #header {{ color: #333; }} | Correct. | CSS |
public static void main(String[] args) {{}} | public static void main(String[] args) {{}} | Correct. | Java |
match b {{ 1 => {{}} }} | match b {{ 1 => {{}} _ => {{}} }} | Match must be exhaustive. | Rust |
val item = 15; item = 83 | var item = 15; item = 83 | Use var for reassignment. | Scala |
raise 'test' | raise Exception('test') | Raise needs an exception class. | Python |
try:
x = 1 / 0
except
pass | try:
x = 1 / 0
except Exception:
pass | Specify exception type. | Python |
<hr></hr> | <hr> | Self-closing. | HTML |
String name = 'data'; | String name = 'data'; | Correct. | Dart |
$x = 5; if ($x -eq 5) { Write-Host 'yes' } | $x = 5; if ($x -eq 5) { Write-Host 'yes' } | Correct. | PowerShell |
echo info hello | echo 'info hello' | Quote to prevent splitting. | Shell |
my @arr = (54,31,11); | my @arr = (54,31,11); | Correct. | Perl |
data[98] | if (data.indices.contains(98)) data[98] | Check index. | Kotlin |
<entry><age>hello</age><age>49</age></entry | <entry><age>hello</age><age>49</age></entry> | Add closing >. | XML |
let mut x=87; let ref1=&mut x; let r2=&mut x; | let mut x=87; {{ let ref1=&mut x; }} let r2=&mut x; | Only one mutable borrow. | Rust |
data(6) | if length(data) >= 6, data(6), end | Check length. | MATLAB |
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