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sizeof can be used to determine the number of elements in an array, by dividing the size of the entire array by the size of a single element. This should be used with caution; When passing an array to another function, it will "decay" to a pointer type. At this point, sizeof will return the size of the pointer, not the total size of the array.
Another, more subtle, difference is the role of the semicolon. In Pascal, semicolons separate individual statements within a compound statement; instead in C, they terminate the statement. In C, they are also syntactically part of the statement (transforming an expression into a statement). This difference manifests mainly in two situations:
The operator sizeof yields a value of the type size_t. The maximum size of size_t is provided via SIZE_MAX , a macro constant which is defined in the < stdint.h > header ( cstdint header in C++). size_t is guaranteed to be at least 16 bits wide.
Returns a substring of string between starting at startpos and endpos, or starting at startpos of length numChars. The resulting string is truncated if there are fewer than numChars characters beyond the starting point. endpos represents the index after the last character in the substring.
In addition the types size_t and ptrdiff_t are defined in relation to the address size to hold unsigned and signed integers sufficiently large to handle array indices and the difference between pointers. ^d Perl 5 does not have distinct types. Integers, floating point numbers, strings, etc. are all considered "scalars".
strlen [28] wcslen [29] Returns the length of the string strcmp [30] wcscmp [31] Compares two strings (three-way comparison) strncmp [32] wcsncmp [33] Compares a specific number of bytes in two strings strcoll [34] wcscoll [35] Compares two strings according to the current locale strchr [36] wcschr [37] Finds the first occurrence of a byte in a ...
Such an idea would make strlen(p+10) (where p is a char* pointer) not work, since the passed pointer is not pointing at the length. You would have to implement a memory model where p+10 produces an object from which the original p and the offset of 10 can be recovered in O(1) time.
Apple's Swift once supported these operators, but they have been depreciated since version 2.2 [13] and removed as of version 3.0. [14] [15]Pascal, Delphi, Modula-2, and Oberon uses functions (inc(x) and dec(x)) instead of operators.