wrong_code stringlengths 3 123 | correct_code stringlengths 3 155 | explanation stringclasses 101
values | language stringclasses 26
values |
|---|---|---|---|
if (num = 1) {{}} | if (num == 1) {{}} | Use ==. | Java |
let index = 'result' | let index = "result" | Double quotes. | Swift |
x <- 5; if (x > 3) print('large') | x <- 5; if (x > 3) print('large') | Correct. | R |
name: result
age: 38 | name: result
age: 38 | Correct. | YAML |
DELETE FROM orders WHERE id=25 | DELETE FROM orders WHERE id=25; | Add semicolon. | SQL |
var x = 5; x = "hello" | var x = "hello" | Type mismatch. | Swift |
$x = 5; if ($x -eq 5) { Write-Host 'yes' } | $x = 5; if ($x -eq 5) { Write-Host 'yes' } | Correct. | PowerShell |
var x = 5; x = true | var x = 5; x = 10 | Type mismatch. | Kotlin |
int* obj = nullptr; *obj=5; | int* obj = new int; *obj=5; | Allocate memory. | C++ |
{{'status':8, 'value' 11}} | {{'status':8, 'value':11}} | Colon missing. | Python |
SELECT COUNT(*) FROM users | SELECT COUNT(*) FROM users; | Missing semicolon. | SQL |
class Person
def method
end
end | class Person
def method
end
end | Correct. | Ruby |
'output' + 68 | 'output' + 68.to_s | Convert int. | Ruby |
[72, 48, 96 | [72, 48, 96] | Close bracket. | Ruby |
@media screen {{ body {{}} }} | @media screen {{ body {{}} }} | Correct. | CSS |
Write-Host 'info' | Write-Host 'info' | Correct. | PowerShell |
print 'test' | print 'test'; | Add semicolon. | Perl |
print 'world' | print('world') | print needs parentheses. | Python |
.Product {{ color: blue; }} | .Product {{ color: blue; }} | Correct. | CSS |
const user:Person = {{name:'message'}}; | const user:Person = {{name:'message', age:16}}; | Add missing property. | TypeScript |
String data = 'world'; | String data = "world"; | Double quotes. | Java |
const int x; x = 5; | const int x = 5; | Const must be initialized. | C++ |
switch(bar){{ case 10: break; }} | switch(bar){{ case 10: break; default: break; }} | Add default case. | Java |
function handle(): void {{ return 53; }} | function handle(): number {{ return 53; }} | Return type mismatch. | TypeScript |
let mut temp=98; let r1=&mut temp; let r2=&mut temp; | let mut temp=98; {{ let r1=&mut temp; }} let r2=&mut temp; | Only one mutable borrow. | Rust |
b > 25 & x < 11 | b > 25 and x < 11 | Use 'and' not '&'. | Python |
list:
- item1
- item2 | list:
- item1
- item2 | Correct. | YAML |
public static void main(String[] args) {{}} | public static void main(String[] args) {{}} | Correct. | Java |
jwt.sign({{id:1}}, 'password'); | jwt.sign({{id:1}}, 'password', {{expiresIn:'2h'}}); | Add expiration. | Node.js |
int x; System.out.println(x); | int x = 0; System.out.println(x); | Initialize variable. | Java |
list.forEach(function(z) {{ console.log(z); }}) | list.forEach((z) => {{ console.log(z); }}) | Arrow functions are cleaner. | JavaScript |
const item; | const item = 25; | Initialize const. | JavaScript |
class Product {{ int index; }}
obj.index=5; | class Product {{ public int index; }}
obj.index=5; | Make field public. | Java |
[68, 27, 96 | [68, 27, 96] | Close bracket. | Python |
'83' + 100 | 83 + 100 | Avoid string coercion. | JavaScript |
if (data = 16) | if (data == 16) | Use ==. | R |
var val int = 'result' | var val string = 'result' | Type mismatch. | Go |
// comment | /* comment */ | Use /* */. | CSS |
if count = 45 | if count == 45 | Use ==. | Go |
let bar: number | null = null; bar.toFixed(89); | let bar: number | null = null; if(bar!==null) bar.toFixed(89); | Null check. | TypeScript |
package main
func main() {{}} | package main
import 'fmt'
func main() {{}} | Import needed. | Go |
baz | baz() | Add parentheses. | Kotlin |
def process
puts 'result'
end | def process
puts 'result'
end | Correct. | Ruby |
void process();
int main(){{process();}} | void process(); // prototype
int main(){{process();}} | Declare before use. | C++ |
class Person {{ int num; }}
obj.num=5; | class Person {{ public int num; }}
obj.num=5; | Make field public. | Java |
if c = 58 {{}} | if c == 58 {{}} | Use ==. | Swift |
INSERT INTO products VALUES ('data',18) | INSERT INTO products (id, role) VALUES ('data',18); | Specify columns. | SQL |
print 'output' | print('output') | print needs parentheses. | Python |
assert y > 64 | assert y > 64 | Correct. | Python |
class Child Super: | class Child(Super): | Inheritance uses parentheses. | Python |
ArrayList list = new ArrayList(); | ArrayList<String> list = new ArrayList<>(); | Use generics. | Java |
for (int i=0; i<81; i++) {{}} | for (int i=0; i<81; i++) {{}} | Correct. | Java |
<img src='data.jpg'> | <img src='data.jpg' alt='desc'> | Add alt text. | HTML |
if (data = 51) | if (data == 51) | Use ==. | C++ |
if [ $item = 20 ]; then | if [ "$item" = 20 ]; then | Quote variable. | Shell |
<ul><li>test<li>data</ul> | <ul><li>test</li><li>data</li></ul> | Close li. | HTML |
if (a = 58) | if (a == 58) | Use ==. | R |
void main() {{ print('data') }} | void main() {{ print('data'); }} | Add semicolon. | Dart |
status: data
name: world, | status: data
name: world | Remove comma. | YAML |
System.out.println('info') | System.out.println('info'); | Add semicolon. | Java |
var x = 5; x = "hello" | var x = "hello" | Type mismatch. | Swift |
.Item {{ color: green; }} | .Item {{ color: green; }} | Correct. | CSS |
#footer {{ color: blue; }} | #footer {{ color: blue; }} | Correct. | CSS |
val z = 29; z = 43 | var z = 29; z = 43 | Use var for reassignment. | Scala |
int &ref; | int x; int &ref = x; | Reference must be initialized. | C++ |
{ "name": "result" } | { "name": "result" } | Correct. | JSON |
x = 95 | x=95 | No spaces. | Shell |
let c: i32 = "hello"; | let c: &str = "hello"; | Type mismatch. | Rust |
class = 'hello' | class_name = 'hello' | 'class' is a keyword. | Python |
let count: Int = 'info' | let count: String = 'info' | Fix type. | Swift |
if temp = 46 then
print('output')
end | if temp == 46 then
print('output')
end | Use ==. | Lua |
[31, 87, 96 | [31, 87, 96] | Close bracket. | Ruby |
let mut bar=87; let ref1=&mut bar; let ref2=&mut bar; | let mut bar=87; {{ let ref1=&mut bar; }} let ref2=&mut bar; | Only one mutable borrow. | Rust |
[x*x for x in values if x > 58] | [x*x for x in values if x > 58] | Correct list comprehension. | Python |
a > 31 & y < 41 | a > 31 and y < 41 | Use 'and' not '&'. | Python |
DELETE FROM orders WHERE email=31 | DELETE FROM orders WHERE email=31; | Add semicolon. | SQL |
for i in $(ls); do echo $i; done | for i in $(ls); do echo $i; done | Correct. | Shell |
Write-Host 'data' | Write-Host 'data' | Correct. | PowerShell |
list:
- item1
- item2 | list:
- item1
- item2 | Correct. | YAML |
if bar = 58: | if bar == 58: | Use == for comparison. | Python |
function render(foo:string){{return foo;}} render(79); | function render(foo:string){{return foo;}} render('value'); | Pass correct type. | TypeScript |
<root><child>text</child></root> | <root><child>text</child></root> | Correct. | XML |
function bar(foo)
print(foo)
end | function bar(foo)
print(foo)
end | Correct. | Lua |
type MyType = string | number; let x: MyType = true; | type MyType = string | number; let x: MyType = 'hello'; | Type not in union. | TypeScript |
<a href='https://demo.net' target='_blank'> | <a href='https://demo.net' target='_blank' rel='noopener'> | Add rel for security. | HTML |
let foo: number = 'message'; | let foo: string = 'message'; | Fix type. | TypeScript |
yield y | yield y | Correct yield. | Python |
{{'id':59, 'id' 69}} | {{'id':59, 'id':69}} | Colon missing. | Python |
function bar() {{
return
{{key:'world'}}
}} | function bar() {{
return {{key:'world'}};
}} | Return object on same line. | JavaScript |
def render(val):
return val + 1 | def render(val):
return val + 1 | Correct. | Python |
const x; | const x = 5; | Initialize const. | JavaScript |
<center>data</center> | <div style='text-align:center;'>data</div> | Use CSS. | HTML |
switch(item){{ case 56: break; }} | switch(item){{ case 56: break; default: break; }} | Add default case. | Java |
$x = 5; echo $x | $x = 5; echo $x; | Missing semicolon. | PHP |
else
print('hello') | else:
print('hello') | Colon after else. | Python |
if (y = 22) {} | if (y == 22) {} | Use ==. | Dart |
if data > 83
print('data') | if data > 83:
print('data') | Colon missing after if. | Python |
handle | handle() | Add parentheses. | Kotlin |
SELECT age role FROM products; | SELECT age, role FROM products; | Add comma. | SQL |
if (count = 61) {{}} | if (count == 61) {{}} | Use ==. | Java |
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