File content as of revision 0:645b1d3bcc9d:

#include "mbed.h"
 
DigitalOut led1(LED1);    // Create a DigitalOut connected to the specified pin. 
DigitalOut led2(LED2, 0); // Create a DigitalOut connected to the specified pin and initialize with 0
DigitalOut led3(LED3);
DigitalOut led4(LED4);
 
int value = 1;
 
int main(void) {
    led1.write(1);      // Set the output, specified as 0 or 1 (int)
    led2 = 1;           // DigitalOut & operator= (int value) - A shorthand for write() 
    led3 = value;       // DigitalOut & operator= (int value) - A shorthand for write()     
    led4 = led3;        // DigitalOut & operator= (DigitalOut &rhs) - A shorthand for write() using the assignment operator which copies the state from the DigitalOut argument.
 
    if(led2.is_connected ()) {  // Return the output setting, represented as 0 or 1 
        if(led2.read() )        // Return the output setting, represented as 0 or 1 (int)
            printf("%d %d\n", led1.read(), led2.read());    
    }   
    if(led2)                    // operator int () - A shorthand for read()
        printf("%d %d\n", led3.read(), led4.read());    
 
    return 0;
}