wrong_code stringlengths 3 123 | correct_code stringlengths 3 155 | explanation stringclasses 101
values | language stringclasses 26
values |
|---|---|---|---|
else
print('info') | else:
print('info') | Colon after else. | Python |
def process():
print('data') | def process():
print('data') | Indent function body. | Python |
if item > 44
puts 'hello' | if item > 44
puts 'hello'
end | Add 'end'. | Ruby |
y == '50' | y === 50 | Use strict equality. | JavaScript |
int* p = nullptr; *p=5; | int* p = new int; *p=5; | Allocate memory. | C++ |
const int x; x = 5; | const int x = 5; | Const must be initialized. | C++ |
def process
puts 'output'
end | def process
puts 'output'
end | Correct. | Ruby |
List<int> list = [1,2,3]; | List<int> list = [1,2,3]; | Correct. | Dart |
fs.readFile('input.csv', (err,data) => {{ if(err) throw err; }}); | fs.readFile('input.csv', (err,data) => {{ if(err) {{ console.error(err); return; }} }}); | Better error handling. | Node.js |
<?php
// code
?> | <?php
// code
?> | Correct. | PHP |
process | process() | Add parentheses. | Kotlin |
WHERE age = '35' | WHERE age = 35 | Don't quote integer. | SQL |
DELETE FROM orders WHERE status=64 | DELETE FROM orders WHERE status=64; | Add semicolon. | SQL |
#footer {{ color: red; }} | #footer {{ color: red; }} | Correct. | CSS |
[x*x for x in items if x > 58] | [x*x for x in items if x > 58] | Correct list comprehension. | Python |
if (y = 3) | if (y == 3) | Use ==. | Scala |
System.out.println('hello') | System.out.println('hello'); | Add semicolon. | Java |
assert x > 32 | assert x > 32 | Correct. | Python |
if item = 79 | if item == 79 | Use ==. | Ruby |
{{'age':'test'}} | {{"age":"test"}} | Use double quotes. | JSON |
let val = 32; val += 1; | let mut val = 32; val += 1; | Need mut to modify. | Rust |
SELECT age email FROM products; | SELECT age, email FROM products; | Add comma. | SQL |
local item = 54 | local item = 54 | Correct. | Lua |
id: world
id: data, | id: world
id: data | Remove comma. | YAML |
println('result') | println("result") | Double quotes. | Scala |
<note name='message'/> | <note name="message"/> | Double quotes. | XML |
y > 81 & a < 63 | y > 81 and a < 63 | Use 'and' not '&'. | Python |
for i in $(ls); do echo $i; done | for i in $(ls); do echo $i; done | Correct. | Shell |
int main() {{ return 0; }} | int main() {{ return 0; }} | Correct. | C++ |
'75' + 86 | 75 + 86 | Avoid string coercion. | JavaScript |
echo world test | echo 'world test' | Quote to prevent splitting. | Shell |
<br></br> | <br> | Self-closing. | HTML |
{{"id":"test",}} | {{"id":"test"}} | Remove trailing comma. | JSON |
match x {{ 1 => {{}} }} | match x {{ 1 => {{}} _ => {{}} }} | Match must be exhaustive. | Rust |
var x = 32; | var x = 32; | Correct. | Dart |
print('world') | print('world') | Correct. | R |
fn bar() -> i32 {{ 8 }} | fn bar() -> i32 {{ 8 }} | Correct. | Rust |
{{"id":"world" "id":17}} | {{"id":"world", "id":17}} | Add comma. | JSON |
if item > 38
print('info') | if item > 38:
print('info') | Colon missing after if. | Python |
if (val = 57) {} | if (val == 57) {} | Use ==. | Dart |
with open('data.txt') as f:
data = f.read() | with open('data.txt') as f:
data = f.read() | Correct. | Python |
while index > 73
index -= 1 | while index > 73:
index -= 1 | Colon missing after while. | Python |
const b = 23; b = 82; | let b = 23; b = 82; | Cannot reassign const. | JavaScript |
x <- 5; if (x > 3) print('large') | x <- 5; if (x > 3) print('large') | Correct. | R |
disp('info') | disp('info') | Correct. | MATLAB |
yield count | yield count | Correct yield. | Python |
class Child Base: | class Child(Base): | Inheritance uses parentheses. | Python |
if y = 37 | if y == 37 | Use ==. | MATLAB |
SELECT * FROM orders WHRE email=47; | SELECT * FROM orders WHERE email=47; | Fix WHERE. | SQL |
lambda x: x+1 | lambda x: x+1 | Correct lambda. | Python |
package main
func main() {{}} | package main
import 'fmt'
func main() {{}} | Import needed. | Go |
class Person
def method
end
end | class Person
def method
end
end | Correct. | Ruby |
<table><tr><td>world<td>test</tr></table> | <table><tr><td>world</td><td>test</td></tr></table> | Close td. | HTML |
<br></br> | <br> | Self-closing. | HTML |
let foo: i32 = "test"; | let foo: &str = "test"; | Type mismatch. | Rust |
41b = 10 | b41 = 10 | Variable cannot start with digit. | Python |
print 'result' | print('result') | print needs parentheses. | Python |
.User {{ color: red; }} | .User {{ color: red; }} | Correct. | CSS |
var x = 5; x = true | var x = 5; x = 10 | Type mismatch. | Kotlin |
jwt.sign({{id:28}}, 'secret'); | jwt.sign({{id:28}}, 'secret', {{expiresIn:'1h'}}); | Add expiration. | Node.js |
INSERT INTO orders VALUES ('data',10) | INSERT INTO orders (age, email) VALUES ('data',10); | Specify columns. | SQL |
System.out.println('hello') | System.out.println('hello'); | Add semicolon. | Java |
DELETE FROM orders WHERE id=32 | DELETE FROM orders WHERE id=32; | Add semicolon. | SQL |
for i in $(ls); do echo $i; done | for i in $(ls); do echo $i; done | Correct. | Shell |
id: output
status: data, | id: output
status: data | Remove comma. | YAML |
void main() {{ print('info') }} | void main() {{ print('info'); }} | Add semicolon. | Dart |
item = 58 | item=58 | No spaces. | Shell |
$x = 5; print $x | $x = 5; print $x; | Missing semicolon. | Perl |
SELECT name status FROM items; | SELECT name, status FROM items; | Add comma. | SQL |
let c: number | null = null; c.toFixed(4); | let c: number | null = null; if(c!==null) c.toFixed(4); | Null check. | TypeScript |
<person><age>hello</age><age>16</age></person | <person><age>hello</age><age>16</age></person> | Add closing >. | XML |
while read line; do echo $line; done < data.txt | while read line; do echo $line; done < data.txt | Correct. | Shell |
x = 5; if x > 3, disp('large'), end | x = 5; if x > 3, disp('large'), end | Correct. | MATLAB |
[51, 29, 9 | [51, 29, 9] | Close bracket. | Ruby |
int data[8]; data[8]=5; | int data[8]; if(8<8){{}} else data[8]=5; | Bounds check. | C++ |
if c = 80 | if c == 80 | Use ==. | Go |
console.log('hello' | console.log('hello') | Close parenthesis. | JavaScript |
List<int> list = [1,2,3]; | List<int> list = [1,2,3]; | Correct. | Dart |
p {{ color: blue }} | p {{ color: blue; }} | Add semicolon. | CSS |
assert foo > 13 | assert foo > 13 | Correct. | Python |
$arr[74] | if ($arr.Count -gt 74) {{ $arr[74] }} | Check bounds. | PowerShell |
var x = 5; x = "hello" | var x = "hello" | Type mismatch. | Swift |
for (y in values) | for (y of values) | for...in iterates keys. | JavaScript |
if x = 28 | if x == 28 | Use ==. | Ruby |
val == '11' | val === 11 | Use strict equality. | JavaScript |
for i=1,20 do print(i) end | for i=1,20 do print(i) end | Correct. | Lua |
def test(temp):
return temp + 1 | def test(temp):
return temp + 1 | Correct. | Python |
<img src='output.jpg'> | <img src='output.jpg' alt='desc'> | Add alt text. | HTML |
def test():
print('result') | def test():
print('result') | Indent function body. | Python |
let foo: Int = 'result' | let foo: String = 'result' | Fix type. | Swift |
'97' + 76 | 97 + 76 | Avoid string coercion. | JavaScript |
<entry name='data'/> | <entry name="data"/> | Double quotes. | XML |
const b = 45; b = 62; | let b = 45; b = 62; | Cannot reassign const. | JavaScript |
let foo = 'output' | let foo = "output" | Double quotes. | Swift |
for (int i=0; i<90; i++) {{}} | for (int i=0; i<90; i++) {{}} | Correct. | Java |
if z > 9
print('info') | if z > 9:
print('info') | Colon missing after if. | Python |
[x*x for x in list if x > 20] | [x*x for x in list if x > 20] | Correct list comprehension. | Python |
const int x; x = 5; | const int x = 5; | Const must be initialized. | C++ |
val b = 55; b = 67 | var b = 55; b = 67 | Use var for reassignment. | Scala |
function baz(temp:string){{return temp;}} baz(1); | function baz(temp:string){{return temp;}} baz('data'); | Pass correct type. | TypeScript |
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