大约有 43,000 项符合查询结果（耗时：0.0274秒） [XML]
Why does String.valueOf(null) throw a NullPointerException?
...ring.valueOf method is overloaded:
String.valueOf(Object)
String.valueOf(char[])
Java Specification Language mandates that in these kind of cases, the most specific overload is chosen:
JLS 15.12.2.5 Choosing the Most Specific Method
If more than one member method is both accessible and app...
Calling constructors in c++ without new
...new object on the stack by calling a constructor of the format Thing(const char*).
The second one is a bit more complex. It essentially does the following
Create an object of type Thing using the constructor Thing(const char*)
Create an object of type Thing using the constructor Thing(const Th...
Joining three tables using MySQL
...
SELECT
employees.id,
CONCAT(employees.f_name," ",employees.l_name) AS 'Full Name', genders.gender_name AS 'Sex',
depts.dept_name AS 'Team Name',
pay_grades.pay_grade_name AS 'Band',
designations.designation_name AS 'Role'
FROM employees
LE...
What is the JavaScript equivalent of var_dump or print_r in PHP? [duplicate]
...ple 1: var_dump(1);
// returns 1: 'int(1)'
var output = '',
pad_char = ' ',
pad_val = 4,
lgth = 0,
i = 0;
var _getFuncName = function(fn) {
var name = (/\W*function\s+([\w\$]+)\s*\(/)
.exec(fn);
if (!name) {
return '(Anonymous)';
}
return name[1]...
内存调试技巧：C 语言最大难点揭秘 - C/C++ - 清泛网 - 专注C/C++及内核技术
...
清单 1. 简单的潜在堆内存丢失和缓冲区覆盖
void f1(char *explanation)
{
char p1;
p1 = malloc(100);
(void) sprintf(p1,
"The f1 error occurred because of '%s'.",
explanation);
loca...
Split string into array of character strings
I need to split a String into an array of single character Strings.
11 Answers
11
...
Please explain the exec() function and its family
...ed by the caller
You can mix them, therefore you have:
int execl(const char *path, const char *arg, ...);
int execlp(const char *file, const char *arg, ...);
int execle(const char *path, const char *arg, ..., char * const envp[]);
int execv(const char *path, char *const argv[]);
int execvp(const...
#pragma pack effect
...example, given 4-byte integers and the following struct:
struct Test
{
char AA;
int BB;
char CC;
};
The compiler could choose to lay the struct out in memory like this:
| 1 | 2 | 3 | 4 |
| AA(1) | pad.................. |
| BB(1) | BB(2) | BB(3) | BB(4) |
| CC(1) | pa...
static constructors in C++? I need to initialize private static objects
... a class with a private static data member (a vector that contains all the characters a-z). In java or C#, I can just make a "static constructor" that will run before I make any instances of the class, and sets up the static data members of the class. It only gets run once (as the variables are read...
Get all table names of a particular database by SQL query?
...n I have different table schemata within one database (SQL Server): SELECT CONCAT(TABLE_SCHEMA, '.', TABLE_NAME) FROM INFORMATION_SCHEMA.TABLES WHERE TABLE_TYPE = 'BASE TABLE' AND TABLE_CATALOG='MyDB'
– Verena Haunschmid
Aug 10 '15 at 8:08
...