Online C/C++ Editor and Compiler - Code in C++

Free online C/C++ editor with real-time compilation, console output, and standard library support. Perfect for learning C++, testing algorithms, and practicing memory management.

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Features

Code Execution

Execute C/C++ code directly in your browser

Console Output

Real-time console output with stdio support

Standard Library

Access to C++ standard library functions

Error Detection

Detailed compilation and runtime error messages

Memory Safety

Safe execution environment for memory operations

Code Sharing

Share C/C++ code snippets with others

Frequently Asked Questions

What C++ features are supported in the WebAssembly environment?

The C++ WebAssembly environment supports:

Basic C++ classes with encapsulation and inheritance
Member functions and constructors
References and basic polymorphism
Templates for simple functions
Traditional C features (structs, pointers)
Basic memory management

Example of supported code:

#include <stdio.h>

class Person {
private:
    char name[100];
    int age;

public:
    Person(const char* n, int a) {
        strcpy(name, n);
        age = a;
    }

    void display() {
        printf("Name: %s, Age: %d\n", name, age);
    }
};

What C++ features should I avoid in this environment?

The following features may cause compilation errors or runtime issues:

Standard Template Library (STL) containers (vector, map)
Complex I/O streams (iostream, stringstream)
Exception handling (try/catch)
RTTI (Run-Time Type Information)
Multiple inheritance
Lambda expressions
Threading and synchronization
File I/O operations

Why am I getting 'process exited with code 1' errors?

This error typically occurs when:

Using unsupported C++ features or libraries
Improper memory management causing segmentation faults
Stack overflow from large recursive calls
Using unimplemented library functions

Try using this more reliable approach:

#include <stdio.h>
#include <stdlib.h>

struct Person {
    char name[100];
    int age;
};

void displayPerson(struct Person* p) {
    printf("Name: %s, Age: %d\n", p->name, p->age);
}

int main() {
    struct Person person = {"John", 30};
    displayPerson(&person);
    return 0;
}

Do I need to include 'using namespace std;'?

For maximum compatibility:

Use C-style functions instead of C++ streams
If using C++ features, prefer explicit namespaces

// Instead of this (may not work):
#include <iostream>
using namespace std;
cout << "Hello" << endl;

// Use this (more reliable):
#include <stdio.h>
printf("Hello\n");

How should I handle memory in WebAssembly C++?

Best practices for memory management:

Prefer stack allocation when possible
Keep track of all memory allocations
Match each new/malloc with delete/free
Avoid complex memory patterns

Example of proper memory management:

#include <stdlib.h>
#include <stdio.h>

int main() {
    // Stack allocation (safer)
    int numbers[5] = {1, 2, 3, 4, 5};

    // Dynamic allocation (needs careful management)
    int* data = (int*)malloc(5 * sizeof(int));
    if (data) {
        for (int i = 0; i < 5; i++) {
            data[i] = i * 10;
        }
        // Always free allocated memory
        free(data);
    }
    return 0;
}

How can I debug compilation issues?

If your code doesn't compile or run:

Start with a minimal example
Try using C alternatives to C++ features (printf vs cout)
Check that all necessary headers are included
Look for syntax differences between C and C++
Try refreshing the page if you get random errors

Debugging approach:

#include <stdio.h>

int main() {
    // Add print statements to trace execution
    printf("Starting program\n");

    int x = 10;
    printf("x = %d\n", x);

    // Check intermediate results
    int result = x * 5;
    printf("result = %d\n", result);

    return 0;
}