Learn EMSCRIPTEN with Real Code Examples

# emscripten/demo/add.c
#include <emscripten/emscripten.h>

EMSCRIPTEN_KEEPALIVE
int add(int a, int b) {
    return a + b;
}

A basic C function that adds two numbers and returns the result, compiled with Emscripten.

# emscripten/demo/subtract.c
#include <emscripten/emscripten.h>

EMSCRIPTEN_KEEPALIVE
int subtract(int a, int b) {
    return a - b;
}

Subtracts one integer from another.

# emscripten/demo/multiply.c
#include <emscripten/emscripten.h>

EMSCRIPTEN_KEEPALIVE
int multiply(int a, int b) {
    return a * b;
}

Multiplies two integers and returns the result.

# emscripten/demo/divide.c
#include <emscripten/emscripten.h>

EMSCRIPTEN_KEEPALIVE
int divide(int a, int b) {
    return a / b;
}

Divides one integer by another, integer division.

# emscripten/demo/factorial.c
#include <emscripten/emscripten.h>

EMSCRIPTEN_KEEPALIVE
int factorial(int n) {
    if(n <= 1) return 1;
    return n * factorial(n - 1);
}

Calculates factorial of a number recursively.

# emscripten/demo/fibonacci.c
#include <emscripten/emscripten.h>

EMSCRIPTEN_KEEPALIVE
int fibonacci(int n) {
    if(n <= 1) return n;
    return fibonacci(n - 1) + fibonacci(n - 2);
}

Calculates Fibonacci number recursively.

# emscripten/demo/isEven.c
#include <emscripten/emscripten.h>

EMSCRIPTEN_KEEPALIVE
int isEven(int n) {
    return (n % 2) == 0;
}

Returns 1 if a number is even, 0 otherwise.

# emscripten/demo/isOdd.c
#include <emscripten/emscripten.h>

EMSCRIPTEN_KEEPALIVE
int isOdd(int n) {
    return (n % 2) != 0;
}

Returns 1 if a number is odd, 0 otherwise.

# emscripten/demo/max.c
#include <emscripten/emscripten.h>

EMSCRIPTEN_KEEPALIVE
int max(int a, int b) {
    return a > b ? a : b;
}

Returns the maximum of two integers.

# emscripten/demo/min.c
#include <emscripten/emscripten.h>

EMSCRIPTEN_KEEPALIVE
int min(int a, int b) {
    return a < b ? a : b;
}

Returns the minimum of two integers.