char and string problem

Using Arduino Programming Questions
1

Hi, I want to save "b" in "a" .
But I don't know how can I do that.

const char *a="";
String b="ABCDEF";

Very thank you.

2

Why do you want to mix strings (lowercase s) and Strings (uppercase S) ?

3

actually the variable "*a" is an input of a function and the variable "b" is output of a function.
so I want to save value of variable "b" in variable "*a".
thanks.

4

leoncorleone:
actually the variable "*a" is an input of a function and the variable "b" is output of a function.
so I want to save value of variable "b" in variable "*a".
thanks.

post your code and I'll show you. I'm not typing out your whole sketch!

5 
char *str1;
char str2[10]="123456789";

Now I want to put str2 in str1.
but how?

6

leoncorleone:

char *str1;

char str2[10]="123456789";



Now I want to put str2 in str1.

You can not put an array of twenty characters into a pointer to a character.

7

Whandall:
You can not put an array of twenty characters into a pointer to a character.

you can point to that array with the pointer, however...

  char str2[10]="123456789";
  char* str1;
  str1 = str2;
  Serial.println(str1);
8

BulldogLowell:
you can point to that array with the pointer, however...

How is that connected to

Now I want to put str2 in str1.

?

9

Whandall:
How is that connected to
?

because str1 now points to what str2 points to.

They are both just pointers ;D

10

BulldogLowell:
They are both just pointers ;D

No, they are not.

One is a character array (its name can be used as a pointer constant),
the other is a pointer to a character.

11

The OP seems to have a number of threads on this subject open which is confusing. In addition there has been no complete program posted in any of them or an explanation of why he/she wants to do what they are asking so any answers are not in context and other solutions may be more appropriate.

12

Whandall:
One is a character array (its name can be used as a pointer constant),

exactly!

as was done

13

I see a big difference in

"can be used as a pointer constant"

and

"is a pointer"

But that's only my humble opinion.

14

Whandall:
I see a big difference in

"can be used as a pointer constant"

and

"is a pointer"

But that's only my humble opinion.

Tomayto Tomahto.

A rose by any other name would smell as sweet

OP may be looking to pass a pointer to a char array to a function (but who the heck knows what he wants!!!

15

The fact that your tooth brush could be used to clean the toilet does not make it a toilet brush, does it?

The OP probably has an assignment to enumerate and understand the differences between

  • charachters
  • character arrays
  • pointer to characters
  • Strings
    but as you already noted, who knows?
16

Whandall:
[/list]but as you already noted, who knows?

I'm only posting this in order to have the last word.