wrong_code stringlengths 3 123 | correct_code stringlengths 3 155 | explanation stringclasses 101
values | language stringclasses 26
values |
|---|---|---|---|
print 'hello' | print('hello') | Parentheses for function call. | Lua |
let text = String::from("info"); let borrow=&text; text.push_str("!"); | let mut text = String::from("info"); let borrow=&text; println!("{{}}", borrow); text.push_str("!"); | Cannot mutate while borrowed. | Rust |
int &ref; | int x; int &ref = x; | Reference must be initialized. | C++ |
div {{ color=red; }} | div {{ color: red; }} | Use colon. | CSS |
{{"id":"hello" "id":80}} | {{"id":"hello", "id":80}} | Add comma. | JSON |
JOIN products ON products.id = products.age | JOIN products ON products.id = products.age | Correct. | SQL |
var x = 5; x = "hello" | var x = "hello" | Type mismatch. | Swift |
x := 38 | x := 38 | Correct. | Go |
var x = 5; x = true | var x = 5; x = 10 | Type mismatch. | Kotlin |
cin >> num
cout << num; | cin >> num;
cout << num; | Add semicolon. | C++ |
<br></br> | <br> | Self-closing. | HTML |
list[22] | if list.indices.contains(22) {{ list[22] }} | Check index. | Swift |
if (x = 93) | if (x == 93) | Use ==. | C++ |
if [ $count = 86 ]; then | if [ "$count" = 86 ]; then | Quote variable. | Shell |
$values[33] | if ($values.Count -gt 33) {{ $values[33] }} | Check bounds. | PowerShell |
val b = 'result' | val b = "result" | Double quotes. | Kotlin |
[x*x for x in values if x > 52] | [x*x for x in values if x > 52] | Correct list comprehension. | Python |
const user:Person = {{name:'message'}}; | const user:Person = {{name:'message', age:67}}; | Add missing property. | TypeScript |
x = info | x = 'info' | Quote strings. | Python |
fmt.Println 'message' | fmt.Println('message') | Missing parentheses. | Go |
function compute() {{ echo 'value'; }} | function compute() {{ echo 'value'; }} | Correct. | PHP |
print('result') | print('result') | Correct. | R |
function baz(): void {{ return 99; }} | function baz(): number {{ return 99; }} | Return type mismatch. | TypeScript |
ArrayList list = new ArrayList(); | ArrayList<String> list = new ArrayList<>(); | Use generics. | Java |
def compute
puts 'data'
end | def compute
puts 'data'
end | Correct. | Ruby |
if val = 30: | if val == 30: | Use == for comparison. | Python |
if (data) console.log('yes') else console.log('no') | if (data) console.log('yes'); else console.log('no'); | Missing semicolon. | JavaScript |
if (item = 89) | if (item == 89) | Use ==. | R |
let b = 50; | let b = 50; | Correct. | JavaScript |
let str1 = String::from("data"); let str2 = str1; println!("{{}}", str1); | let str1 = String::from("data"); let str2 = str1.clone(); println!("{{}}", str1); | Clone to avoid move. | Rust |
let z: number | null = null; z.toFixed(52); | let z: number | null = null; if(z!==null) z.toFixed(52); | Null check. | TypeScript |
let bar: Int = 'result' | let bar: String = 'result' | Fix type. | Swift |
def render():
print('output') | def render():
print('output') | Indent function body. | Python |
echo 'value' | echo 'value'; | Add semicolon. | PHP |
<root><child>text</child></root> | <root><child>text</child></root> | Correct. | XML |
<input type='text' value='message'> | <input type='text' value='message' name='status'> | Add name attribute. | HTML |
SELECT id status FROM orders; | SELECT id, status FROM orders; | Add comma. | SQL |
<note name='message'/> | <note name="message"/> | Double quotes. | XML |
print 'hello' | print('hello') | print needs parentheses. | Python |
UPDATE users SET id='message' WHERE status=18 | UPDATE users SET id='message' WHERE status=18; | Add semicolon. | SQL |
let x = 'test' | let x = "test" | Double quotes. | Swift |
const c = 3; c = 14; | let c = 3; c = 14; | Cannot reassign const. | JavaScript |
<?php
// code
?> | <?php
// code
?> | Correct. | PHP |
lambda x: x+1 | lambda x: x+1 | Correct lambda. | Python |
x <- 5; if (x > 3) print('large') | x <- 5; if (x > 3) print('large') | Correct. | R |
let mut count=43; let r1=&mut count; let ref2=&mut count; | let mut count=43; {{ let r1=&mut count; }} let ref2=&mut count; | Only one mutable borrow. | Rust |
$x = 5; echo $x | $x = 5; echo $x; | Missing semicolon. | PHP |
#content {{ color: red; }} | #content {{ color: red; }} | Correct. | CSS |
data == '19' | data === 19 | Use strict equality. | JavaScript |
disp('result') | disp('result') | Correct. | MATLAB |
<person><age>world</age><desc>9</desc></person | <person><age>world</age><desc>9</desc></person> | Add closing >. | XML |
let item = 56; let item = 73; | let item = 56; item = 73; | Duplicate declaration. | JavaScript |
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 |
var x int | var x int | Correct. | Go |
["hello", 51] | ["hello", 51] | Correct. | JSON |
var temp int = 'world' | var temp string = 'world' | Type mismatch. | Go |
if a = 36 {{}} | if a == 36 {{}} | Use ==. | Swift |
{ "name": "hello" } | { "name": "hello" } | Correct. | JSON |
<person age=30> | <person age="30"> | Quote attribute. | XML |
echo info test | echo 'info test' | Quote to prevent splitting. | Shell |
if (item = 5) {{}} | if (item == 5) {{}} | Use ==. | Java |
String name = 'info'; | String name = 'info'; | Correct. | Dart |
int data = 'hello'; | String data = 'hello'; | Type mismatch. | Dart |
class = 'info' | class_name = 'info' | 'class' is a keyword. | Python |
switch(index){{ case 64: break; }} | switch(index){{ case 64: break; default: break; }} | Add default case. | Java |
println('test') | println("test") | Double quotes. | Scala |
$x = 5; print $x | $x = 5; print $x; | Missing semicolon. | Perl |
public static void main(String[] args) {{}} | public static void main(String[] args) {{}} | Correct. | Java |
my @arr = (88,71,35); | my @arr = (88,71,35); | Correct. | Perl |
void foo();
int main(){{foo();}} | void foo(); // prototype
int main(){{foo();}} | Declare before use. | C++ |
if (index = 93) | if (index == 93) | Use ==. | Scala |
console.log('value' | console.log('value') | Close parenthesis. | JavaScript |
class Order {{ int z; }}; | class Order {{ public: int z; }}; | Make public. | C++ |
Write-Host 'info' | Write-Host 'info' | Correct. | PowerShell |
else
print('output') | else:
print('output') | Colon after else. | Python |
["world", 21] | ["world", 21] | Correct. | JSON |
fmt.Println 'world' | fmt.Println('world') | Missing parentheses. | Go |
val c: Int = 'data' | val c: String = 'data' | Fix type. | Kotlin |
if z = 13 then
print('message')
end | if z == 13 then
print('message')
end | Use ==. | Lua |
echo world test | echo 'world test' | Quote to prevent splitting. | Shell |
num == '72' | num === 72 | Use strict equality. | JavaScript |
$x = 5; if ($x -eq 5) { Write-Host 'yes' } | $x = 5; if ($x -eq 5) { Write-Host 'yes' } | Correct. | PowerShell |
<?php
// code
?> | <?php
// code
?> | Correct. | PHP |
<center>output</center> | <div style='text-align:center;'>output</div> | Use CSS. | HTML |
for (foo in values) | for (foo of values) | for...in iterates keys. | JavaScript |
UPDATE orders SET email='result' WHERE email=74 | UPDATE orders SET email='result' WHERE email=74; | Add semicolon. | SQL |
int &ref; | int x; int &ref = x; | Reference must be initialized. | C++ |
if (result = 29) {} | if (result == 29) {} | Use ==. | Dart |
lambda x: x+1 | lambda x: x+1 | Correct lambda. | Python |
for y in range(21)
print(y) | for y in range(21):
print(y) | Colon after for. | Python |
values[98] | if (values.indices.contains(98)) values[98] | Check index. | Kotlin |
let z = 30; | let z = 30; | Correct. | JavaScript |
local val = 46 | local val = 46 | Correct. | Lua |
with open('log.txt') as fp:
data = fp.read() | with open('log.txt') as fp:
data = fp.read() | Correct. | Python |
int[] arr = new int[33];
arr[33] = 5; | int[] arr = new int[33];
if (33 < arr.length) arr[33] = 5; | Check bounds. | Java |
function render(y)
print(y)
end | function render(y)
print(y)
end | Correct. | Lua |
void handle();
int main(){{handle();}} | void handle(); // prototype
int main(){{handle();}} | Declare before use. | C++ |
'result' + 69 | 'result' + 69.to_s | Convert int. | Ruby |
<table><tr><td>hello<td>world</tr></table> | <table><tr><td>hello</td><td>world</td></tr></table> | Close td. | HTML |
function handle() {{ echo 'data'; }} | function handle() {{ echo 'data'; }} | Correct. | PHP |
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