Null-Terminated string
Which of the following are null-terminated st开发者_C百科ring?
char *str1 = "This is a string.";
char *str2 = "This is a string.\0";
char str3[] = "This is a string.";
const char *str4 = "This is a string.";
const char *str5 = "This is a string.\0";
const char str6[] = "This is a string.";
- All : a string literal is a null terminated string
str2
andstr5
have the particularity of being doubly null-terminated strings
Also :
char *str1
should beconst char *str1
char *str2
should beconst char *str2
They are all null-terminated (str2
and str5
are actually doubly-null-terminated) because using double quotes is a shorthand for a null-terminated char array.
So this:
"Hello"
Is actually this:
{'H', 'e', 'l', 'l', 'o', '\0'}
Variables pointing to string literals such as these should be declared as const
.
All. C compiler auto aggregates string with a terminate '\0', then store it in a char[] or refer to it by char *;
Don't use char*s="hi"
in case you want to do something with the string like modifying it or even if you want to concatenate something to it because here stringhi
is in read only section of the memory and your program can crash
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