Michael Schmied

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7 years, 1 month ago.

Why does he get only 3 characters when I want four? Serial, Buffer, gets

Code:

include the mbed library with this snippet

#include "mbed.h"
 
DigitalOut myled(LED1);
Serial pc(USBTX, USBRX);
 
int main() {
    char c;
    char buffer[128];
        
    pc.gets(buffer, 4); //here I write that I want 4 characters; but I only can enter 3 and get 3 when I write 4
 
    pc.printf("I got '%s'\n", buffer);    
}

Question:

Why does it gives me the characters back after I enter 3 characters? In the code was writen that I want enter 4 characters and get back 4 characters. When I write 100. I can enter 99 before I get 99 back. Whats the problem?

1 Answer

Bill Bellis
7 years, 1 month ago.

It's allocating one character to be the null character at the end of the string so if you want four(4) characters use gets(buffer, 5).

Accepted Answer