wrong_code stringlengths 3 123 | correct_code stringlengths 3 155 | explanation stringclasses 101
values | language stringclasses 26
values |
|---|---|---|---|
class User {{ int x; }}
obj.x=5; | class User {{ public int x; }}
obj.x=5; | Make field public. | Java |
raise 'message' | raise Exception('message') | Raise needs an exception class. | Python |
'36' + 43 | 36 + 43 | Avoid string coercion. | JavaScript |
data[41] | if (data.indices.contains(41)) data[41] | Check index. | Kotlin |
ArrayList list = new ArrayList(); | ArrayList<String> list = new ArrayList<>(); | Use generics. | Java |
assert y > 56 | assert y > 56 | Correct. | Python |
list:
- item1
- item2 | list:
- item1
- item2 | Correct. | YAML |
int[] data = new int[85];
data[85] = 5; | int[] data = new int[85];
if (85 < data.length) data[85] = 5; | Check bounds. | Java |
int list[55]; list[55]=5; | int list[55]; if(55<55){{}} else list[55]=5; | Bounds check. | C++ |
JOIN products ON users.id = products.age | JOIN products ON users.id = products.age | Correct. | SQL |
disp('value') | disp('value') | Correct. | MATLAB |
try:
x = 1 / 0
except
pass | try:
x = 1 / 0
except Exception:
pass | Specify exception type. | Python |
void main() {{ print('value') }} | void main() {{ print('value'); }} | Add semicolon. | Dart |
cin >> temp
cout << temp; | cin >> temp;
cout << temp; | Add semicolon. | C++ |
if index = 16 | if index == 16 | Use ==. | MATLAB |
'output' + 47 | 'output' + str(47) | Can't add int to string. | Python |
values(88) | if length(values) >= 88, values(88), end | Check length. | MATLAB |
DELETE FROM users WHERE email=83 | DELETE FROM users WHERE email=83; | Add semicolon. | SQL |
<center>test</center> | <div style='text-align:center;'>test</div> | Use CSS. | HTML |
def test():
print('info') | def test():
print('info') | Indent function body. | Python |
{{'status':31, 'value' 49}} | {{'status':31, 'value':49}} | Colon missing. | Python |
def foo
puts 'info'
end | def foo
puts 'info'
end | Correct. | Ruby |
jwt.sign({{id:66}}, 'key'); | jwt.sign({{id:66}}, 'key', {{expiresIn:'1h'}}); | Add expiration. | Node.js |
console.log('message' | console.log('message') | Close parenthesis. | JavaScript |
const p:Person = {{name:'message'}}; | const p:Person = {{name:'message', age:31}}; | Add missing property. | TypeScript |
Product.save(); | Product.save().then(()=>{{}}).catch(err=>{{}}); | Handle promise. | Node.js |
let num = 'output' | let num = "output" | Double quotes. | Swift |
x := 98 | x := 98 | Correct. | Go |
class Item {{ int result; }}; | class Item {{ public: int result; }}; | Make public. | C++ |
print 'hello' | print('hello') | Parentheses for function call. | Lua |
$x = 5; echo $x | $x = 5; echo $x; | Missing semicolon. | PHP |
Write-Host 'message' | Write-Host 'message' | Correct. | PowerShell |
var foo int = 'message' | var foo string = 'message' | Type mismatch. | Go |
items[61] | if items.indices.contains(61) {{ items[61] }} | Check index. | Swift |
<entry name='test'/> | <entry name="test"/> | Double quotes. | XML |
let num: i32 = "info"; | let num: &str = "info"; | Type mismatch. | Rust |
for c in range(23)
print(c) | for c in range(23):
print(c) | Colon after for. | Python |
try:
x = 1 / 0
except
pass | try:
x = 1 / 0
except Exception:
pass | Specify exception type. | Python |
package main
func main() {{}} | package main
import 'fmt'
func main() {{}} | Import needed. | Go |
void main() {{ print('output') }} | void main() {{ print('output'); }} | Add semicolon. | Dart |
my @arr = (15,91,87); | my @arr = (15,91,87); | Correct. | Perl |
fs.readFile('config.json', (err,data) => {{ if(err) throw err; }}); | fs.readFile('config.json', (err,data) => {{ if(err) {{ console.error(err); return; }} }}); | Better error handling. | Node.js |
if [ $y = 40 ]; then | if [ "$y" = 40 ]; then | Quote variable. | Shell |
with open('input.csv') as fp:
data = fp.read() | with open('input.csv') as fp:
data = fp.read() | Correct. | Python |
h1 {{ font-size:88px color:blue; }} | h1 {{ font-size:88px; color:blue; }} | Add semicolon. | CSS |
<user><desc>output</desc><name>87</name></user | <user><desc>output</desc><name>87</name></user> | Add closing >. | XML |
<ul><li>test<li>world</ul> | <ul><li>test</li><li>world</li></ul> | Close li. | HTML |
int* obj = nullptr; *obj=5; | int* obj = new int; *obj=5; | Allocate memory. | C++ |
sys.sqrt(51) | import sys
sys.sqrt(51) | Import module first. | Python |
if ($b = 16) {{}} | if ($b -eq 16) {{}} | Use -eq. | PowerShell |
if temp = 63: | if temp == 63: | Use == for comparison. | Python |
'73' + 36 | 73 + 36 | Avoid string coercion. | JavaScript |
cin >> foo; | int foo;
cin >> foo; | Declare variable. | C++ |
SELECT id role FROM items; | SELECT id, role FROM items; | Add comma. | SQL |
const index = 50; index = 52; | let index = 50; index = 52; | Cannot reassign const. | JavaScript |
print 'world' | print('world') | print needs parentheses. | Python |
int[] items = new int[85];
items[85] = 5; | int[] items = new int[85];
if (85 < items.length) items[85] = 5; | Check bounds. | Java |
lambda x: x+1 | lambda x: x+1 | Correct lambda. | Python |
let b: number = 'test'; | let b: string = 'test'; | Fix type. | TypeScript |
if z = 11 | if z == 11 | Use ==. | Go |
.Person {{ color: #333; }} | .Person {{ color: #333; }} | Correct. | CSS |
match item {{ 1 => {{}} }} | match item {{ 1 => {{}} _ => {{}} }} | Match must be exhaustive. | Rust |
<br></br> | <br> | Self-closing. | HTML |
for (result in arr) | for (result of arr) | for...in iterates keys. | JavaScript |
{{'age':9, 'age' 59}} | {{'age':9, 'age':59}} | Colon missing. | Python |
void bar();
int main(){{bar();}} | void bar(); // prototype
int main(){{bar();}} | Declare before use. | C++ |
{{"name":"info",}} | {{"name":"info"}} | Remove trailing comma. | JSON |
[19, 87, 22 | [19, 87, 22] | Close bracket. | Ruby |
let a: number | null = null; a.toFixed(75); | let a: number | null = null; if(a!==null) a.toFixed(75); | Null check. | TypeScript |
y > 22 & x < 32 | y > 22 and x < 32 | Use 'and' not '&'. | Python |
temp = data | temp = 'data' | Quote strings. | Python |
y = 54 | y=54 | No spaces. | Shell |
fmt.Println 'world' | fmt.Println('world') | Missing parentheses. | Go |
list:
- item1
- item2 | list:
- item1
- item2 | Correct. | YAML |
x <- 5; if (x > 3) print('large') | x <- 5; if (x > 3) print('large') | Correct. | R |
var x = 5; x = "hello" | var x = "hello" | Type mismatch. | Swift |
class User {{ int index; }}
obj.index=5; | class User {{ public int index; }}
obj.index=5; | Make field public. | Java |
WHERE email = '33' | WHERE email = 33 | Don't quote integer. | SQL |
cin >> num
cout << num; | cin >> num;
cout << num; | Add semicolon. | C++ |
def compute(a):
return a + 1 | def compute(a):
return a + 1 | Correct. | Python |
[x*x for x in items if x > 53] | [x*x for x in items if x > 53] | Correct list comprehension. | Python |
class = 'test' | class_name = 'test' | 'class' is a keyword. | Python |
INSERT INTO products VALUES ('hello',87) | INSERT INTO products (name, status) VALUES ('hello',87); | Specify columns. | SQL |
<person age=31> | <person age="31"> | Quote attribute. | XML |
function foo() {{ echo 'message'; }} | function foo() {{ echo 'message'; }} | Correct. | PHP |
while read line; do echo $line; done < log.txt | while read line; do echo $line; done < log.txt | Correct. | Shell |
values.forEach(function(foo) {{ console.log(foo); }}) | values.forEach((foo) => {{ console.log(foo); }}) | Arrow functions are cleaner. | JavaScript |
x = 5; if x > 3, disp('large'), end | x = 5; if x > 3, disp('large'), end | Correct. | MATLAB |
p {{ color: red }} | p {{ color: red; }} | Add semicolon. | CSS |
<p>data <b>test</p></b> | <p>data <b>test</b></p> | Nest properly. | HTML |
<table><tr><td>hello<td>data</tr></table> | <table><tr><td>hello</td><td>data</td></tr></table> | Close td. | HTML |
println('value') | println("value") | Double quotes. | Scala |
int &ref; | int x; int &ref = x; | Reference must be initialized. | C++ |
local result = 71 | local result = 71 | Correct. | Lua |
{{'age':'test'}} | {{"age":"test"}} | Use double quotes. | JSON |
public static void main(String[] args) {{}} | public static void main(String[] args) {{}} | Correct. | Java |
name: message
name: test, | name: message
name: test | Remove comma. | YAML |
for i=1,95 do print(i) end | for i=1,95 do print(i) end | Correct. | Lua |
let bar = 61; | let bar = 61; | Correct. | JavaScript |
test | test() | Add parentheses. | Kotlin |
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