C Language Hao Bin video notes

39:printf% #X的话, the output of the variable is automatically added in front of 0X

scanf if a non-input control character is included, the non-input control is entered as is. So try not to use non-input controls in scanf, especially if you don't use \ n. If you use \ n, enter the data must be entered after the input of a \ n, press Enter no use.

:/ (except), when two integers use this operator, the result is an integer, the fractional part will be discarded, the two numbers that will participate in the operation are floating point numbers or two are floating point numbers, the result is a floating point number.

% (remainder): This operator cannot be used on floating-point numbers. The operand of the remainder must be an integer, the symbol of the remnant is the same as the divisor. That is, the number on the left is the same.

C language is greater than or equal to, less than equals, >=,<=, you used to be greater than or equal to the logic with the greater than and equals to combine. But 1<= a <=10, in C language is wrong, this range to use && write,

Precedence of operators: arithmetic > relationships > logic > Assignment

C language to the true and false processing: non-zero is true.

&&: The left expression is false and the expression on the right is not executed.

|| : The left expression is true and the right expression is not executed.

Neither float nor double can guarantee the exact storage of a decimal, so the variable updated in the loop cannot be defined as a floating-point type.

++i and i++ are separated into a single statement, and do not use it as part of a complete compound statement.

Break:break If the loop is used to terminate the loop, break if used for switch, then it is used to terminate the switch,break cannot be used if, unless the IF belongs to a clause inside the loop. In a multi-layered loop, the break terminates only the nearest loop from him.

Continue: Used to skip the remainder of this loop and go to determine if the next loop needs to be executed.

For a function of type void, a return can also be written inside, but cannot be followed by an expression, only a return is written;

The function of return is to terminate functions, and all statements after return are no longer executed.

Variables defined outside of all functions are called global variables, and global variables are used from the defined position to the end of the entire program.

The parameters of a variable or function defined inside a function or inside a compound statement are collectively referred to as local variables. Scope of use of local variables: can only be used inside this function.

Inside a function, if the name of the defined local variable is the same as the name of the global variable, the local will block out the global variable.

*p a variable with the content of p as the address. The pointer is the address, the address is the pointer, and the address is the number of the memory unit.

Pointers and pointer variables are two different concepts, often referred to as pointers when we describe them, but they do not actually mean the same thing.

Pointer variables cannot be added, cannot be multiplied, cannot be divided, and if two pointer variables point to different storage units in the same contiguous space, then the two pointer variables can be subtracted.

The disadvantage of traditional arrays: 1 array length must be predetermined, and must be a constant integer, cannot be a variable, 2 traditional form defined array, the memory programmer of the array cannot be released manually. The space allocated by the system to the array in the function will persist during a function run, and the space of the array will not be freed until the function has finished running.

Arrays defined in traditional ways cannot be used across functions.

The definition can be assigned as a whole at the same time, and can only be assigned if the definition is complete.

66.6 in the C language, the default is double type, if you want a real number is a float type, then add F or F, written in 66.6f or 66.6F.

When assigning a value to a string variable, it cannot be directly used =, it should be strcpy with a function.

Enumeration variables: Enumerate all possible values of a thing.

C Language Provisions 8 before adding 0 (0 is not the letter O), hexadecimal before the addition of 0X, decimal before anything.

In assembly language, after the number is added Bodh, respectively, 281016 binary,

First node: A node that holds the first valid data

Tail Node: The node that holds the last valid data

Head node: The data type of the head node is the same as the data type of the first node, the first node is the node in front of the first node, the head node does not hold valid data, and the purpose of setting up the head node is to facilitate the operation of the linked list.

Head pointer: A pointer variable that holds the address of the head node.

C Language Hao Bin video notes