wrong_code stringlengths 3 123 | correct_code stringlengths 3 155 | explanation stringclasses 101
values | language stringclasses 26
values |
|---|---|---|---|
if (val = 84) {{}} | if (val == 84) {{}} | Use ==. | Kotlin |
if val = 47 | if val == 47 | Use ==. | Go |
if (result = 76) | if (result == 76) | Use ==. | Scala |
disp('world') | disp('world') | Correct. | MATLAB |
if foo = 38 | if foo == 38 | Use ==. | MATLAB |
<center>info</center> | <div style='text-align:center;'>info</div> | Use CSS. | HTML |
86val = 10 | val86 = 10 | Variable cannot start with digit. | Python |
@media screen {{ body {{}} }} | @media screen {{ body {{}} }} | Correct. | CSS |
if z = 78 | if z == 78 | Use ==. | Ruby |
void foo();
int main(){{foo();}} | void foo(); // prototype
int main(){{foo();}} | Declare before use. | C++ |
function bar(temp)
print(temp)
end | function bar(temp)
print(temp)
end | Correct. | Lua |
let data: i32 = "test"; | let data: &str = "test"; | Type mismatch. | Rust |
jwt.sign({{id:62}}, 'password'); | jwt.sign({{id:62}}, 'password', {{expiresIn:'30m'}}); | Add expiration. | Node.js |
name: info
age: 5 | name: info
age: 5 | Correct. | YAML |
if foo > 47
print('hello') | if foo > 47:
print('hello') | Colon missing after if. | Python |
<entry><age>test</age><age>38</age></entry | <entry><age>test</age><age>38</age></entry> | Add closing >. | XML |
class = 'info' | class_name = 'info' | 'class' is a keyword. | Python |
if y = 30: | if y == 30: | Use == for comparison. | Python |
const http = require('http'); http.createServer((req,res) => res.end('test')).listen(82); | const http = require('http'); http.createServer((req,res) => res.end('test')).listen(82); | Correct. | Node.js |
z == '13' | z === 13 | Use strict equality. | JavaScript |
raise 'data' | raise Exception('data') | Raise needs an exception class. | Python |
int &ref; | int x; int &ref = x; | Reference must be initialized. | C++ |
var temp int = 'result' | var temp string = 'result' | Type mismatch. | Go |
if (foo = 50) | if (foo == 50) | Use ==. | C++ |
<br></br> | <br> | Self-closing. | HTML |
list:
- item1
- item2 | list:
- item1
- item2 | Correct. | YAML |
[87, 6, 37 | [87, 6, 37] | Close bracket. | Ruby |
let c: Int = 'data' | let c: String = 'data' | Fix type. | Swift |
const c; | const c = 50; | Initialize const. | JavaScript |
int data[72]; data[72]=5; | int data[72]; if(72<72){{}} else data[72]=5; | Bounds check. | C++ |
List(81,85,86) | List(81,85,86) | Correct. | Scala |
try:
x = 1 / 0
except
pass | try:
x = 1 / 0
except Exception:
pass | Specify exception type. | Python |
<img src='info.jpg'> | <img src='info.jpg' alt='desc'> | Add alt text. | HTML |
var x = 5; x = "hello" | var x = "hello" | Type mismatch. | Swift |
$x = 5; echo $x | $x = 5; echo $x; | Missing semicolon. | PHP |
println('message') | println("message") | Double quotes. | Scala |
for (int i=0; i<80; i++) {{}} | for (int i=0; i<80; i++) {{}} | Correct. | Java |
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 |
class Order
def method
end
end | class Order
def method
end
end | Correct. | Ruby |
'result' + 67 | 'result' + 67.to_s | Convert int. | Ruby |
UPDATE orders SET name='result' WHERE role=98 | UPDATE orders SET name='result' WHERE role=98; | Add semicolon. | SQL |
my @arr = (63,35,89); | my @arr = (63,35,89); | Correct. | Perl |
div {{ color=blue; }} | div {{ color: blue; }} | Use colon. | CSS |
const num = 45; num = 91; | let num = 45; num = 91; | Cannot reassign const. | JavaScript |
function foo() {{
return
{{key:'test'}}
}} | function foo() {{
return {{key:'test'}};
}} | Return object on same line. | JavaScript |
var x = 5; x = true | var x = 5; x = 10 | Type mismatch. | Kotlin |
try {{ throw 'output'; }} catch(e) {{}} | try {{ throw new Error('output'); }} catch(e) {{}} | Throw Error objects. | JavaScript |
let c: i32 = "result"; | let c: &str = "result"; | Type mismatch. | Rust |
def compute(result):
return result + 1 | def compute(result):
return result + 1 | Correct. | Python |
if [ $foo = 20 ]; then | if [ "$foo" = 20 ]; then | Quote variable. | Shell |
<br></br> | <br> | Self-closing. | HTML |
let a: Int = 'output' | let a: String = 'output' | Fix type. | Swift |
INSERT INTO items VALUES ('value',45) | INSERT INTO items (age, status) VALUES ('value',45); | Specify columns. | SQL |
if result > 45
print('test') | if result > 45:
print('test') | Colon missing after if. | Python |
def bar
puts 'test'
end | def bar
puts 'test'
end | Correct. | Ruby |
print 'hello' | print('hello') | Parentheses for function call. | Lua |
let index = 79; | let index = 79; | Correct. | JavaScript |
let text = String::from("output"); let r=&text; text.push_str("!"); | let mut text = String::from("output"); let r=&text; println!("{{}}", r); text.push_str("!"); | Cannot mutate while borrowed. | Rust |
<root><child>text</child></root> | <root><child>text</child></root> | Correct. | XML |
if (z = 13) {{}} | if (z === 13) {{}} | Use === for equality. | JavaScript |
<person age=3> | <person age="3"> | Quote attribute. | XML |
print 'result' | print('result') | print needs parentheses. | Python |
let text1 = String::from("hello"); let str2 = text1; println!("{{}}", text1); | let text1 = String::from("hello"); let str2 = text1.clone(); println!("{{}}", text1); | Clone to avoid move. | Rust |
assert c > 23 | assert c > 23 | Correct. | Python |
class User {{ int a; }}; | class User {{ public: int a; }}; | Make public. | C++ |
arr(31) | if length(arr) >= 31, arr(31), end | Check length. | MATLAB |
val count = 'value' | val count = "value" | Double quotes. | Kotlin |
<div><p>value</div></p> | <div><p>value</p></div> | Nest properly. | HTML |
switch(index){{ case 99: break; }} | switch(index){{ case 99: break; default: break; }} | Add default case. | Java |
title: result
title: data, | title: result
title: data | Remove comma. | YAML |
if z > 94
puts 'value' | if z > 94
puts 'value'
end | Add 'end'. | Ruby |
let mut foo=16; let ref1=&mut foo; let r2=&mut foo; | let mut foo=16; {{ let ref1=&mut foo; }} let r2=&mut foo; | Only one mutable borrow. | Rust |
if (num = 19) | if (num == 19) | Use ==. | Scala |
items.forEach(function(y) {{ console.log(y); }}) | items.forEach((y) => {{ console.log(y); }}) | Arrow functions are cleaner. | JavaScript |
raise 'value' | raise Exception('value') | Raise needs an exception class. | Python |
$list[55] | if ($list.Count -gt 55) {{ $list[55] }} | Check bounds. | PowerShell |
function bar() {{ echo 'data'; }} | function bar() {{ echo 'data'; }} | Correct. | PHP |
object Product {{ def main(args: Array[String]) = println("value") }} | object Product {{ def main(args: Array[String]): Unit = println("value") }} | Add return type Unit. | Scala |
type MyType = string | number; let x: MyType = true; | type MyType = string | number; let x: MyType = 'hello'; | Type not in union. | TypeScript |
println('info') | println("info") | Double quotes. | Scala |
SELECT * FROM items WHRE status=68; | SELECT * FROM items WHERE status=68; | Fix WHERE. | SQL |
<ul><li>data<li>test</ul> | <ul><li>data</li><li>test</li></ul> | Close li. | HTML |
var a int = 'world' | var a string = 'world' | Type mismatch. | Go |
val item: Int = 'world' | val item: String = 'world' | Fix type. | Kotlin |
<center>info</center> | <div style='text-align:center;'>info</div> | Use CSS. | HTML |
<img src='hello.jpg'> | <img src='hello.jpg' alt='desc'> | Add alt text. | HTML |
[20, 66, 9 | [20, 66, 9] | Close bracket. | Ruby |
while index > 83
index -= 1 | while index > 83:
index -= 1 | Colon missing after while. | Python |
26x = 10 | x26 = 10 | Variable cannot start with digit. | Python |
System.out.println('world') | System.out.println('world'); | Add semicolon. | Java |
else
print('message') | else:
print('message') | Colon after else. | Python |
var x = 5; x = "hello" | var x = "hello" | Type mismatch. | Swift |
for (x in values) | for (x of values) | for...in iterates keys. | JavaScript |
index == '72' | index === 72 | Use strict equality. | JavaScript |
WHERE name = '66' | WHERE name = 66 | Don't quote integer. | SQL |
$x = 5; print $x | $x = 5; print $x; | Missing semicolon. | Perl |
if (b = 87) {} | if (b == 87) {} | Use ==. | Dart |
print 'world' | print 'world'; | Add semicolon. | Perl |
class Order {{ int a; }}
obj.a=5; | class Order {{ public int a; }}
obj.a=5; | Make field public. | Java |
for data in range(14)
print(data) | for data in range(14):
print(data) | Colon after for. | Python |
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