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How can I validate a string to only allow alphanumeric characters in it?
...n I validate a string using Regular Expressions to only allow alphanumeric characters in it?
10 Answers
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strdup() - what does it do in C?
...'s a POSIX thing), it's effectively doing the same as the following code:
char *strdup(const char *src) {
char *dst = malloc(strlen (src) + 1); // Space for length plus nul
if (dst == NULL) return NULL; // No memory
strcpy(dst, src); // Copy the characters...
What is the difference between static_cast and C style casting?
...situations where all that is needed is a simple conversion. The ability to select between several different casting operators of differing degrees of power can prevent programmers from inadvertently casting to an incorrect type.
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How to change string into QString?
...QString::fromStdString(str);
If by string you mean Ascii encoded const char * then you can use this method:
QString QString::fromAscii(const char * str, int size = -1)
const char* str = "Hello world";
QString qstr = QString::fromAscii(str);
If you have const char * encoded with system enco...
How to create CSV Excel file C#? [closed]
...Object = obj;
var line = String.Join(delimeter, propertyInfos.Select(x => SanitizeValuesForCSV(x.GetValue(localObject, null), delimeter)));
sb.AppendLine(line);
}
return sb.ToString();
}
private static string SanitizeValuesForCSV(object value, s...
Types in Objective-C on iOS
...e:
32 bit process:
NSLog(@"Primitive sizes:");
NSLog(@"The size of a char is: %d.", sizeof(char));
NSLog(@"The size of short is: %d.", sizeof(short));
NSLog(@"The size of int is: %d.", sizeof(int));
NSLog(@"The size of long is: %d.", sizeof(long));
NSLog(@"The size of long long is: %d....
How to make vim paste from (and copy to) system's clipboard?
...system clipboard. On X11 systems both registers can be used. See :help x11-selection for more details, but basically the "* is analogous to X11's _PRIMARY_ selection (which usually copies things you select with the mouse and pastes with the middle mouse button) and "+ is analogous to X11's _CLIPBOAR...
Single quotes vs. double quotes in C or C++
...
In C and in C++ single quotes identify a single character, while double quotes create a string literal. 'a' is a single a character literal, while "a" is a string literal containing an 'a' and a null terminator (that is a 2 char array).
In C++ the type of a character lite...
Count the number occurrences of a character in a string
What's the simplest way to count the number of occurrences of a character in a string?
19 Answers
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How can I increment a char?
I'm new to Python, coming from Java and C. How can I increment a char? In Java or C, chars and ints are practically interchangeable, and in certain loops, it's very useful to me to be able to do increment chars, and index arrays by chars.
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