number.
That is to say, a constant or infinity should be added to an infinity, and 0x7fffff + 1 will overflow. Obviously, this does not meet this basic requirement.
So we found 0x3f3f3f3f (which is the first big God to use this number). Its value is 1061109567, that is, 10 ^ 9, which is an order of magnitude higher than 0x7fffffff, it adds a constant still in the range of 32int... more importantly, an infi
back the ancient Ancient ancient Greece 2000 years ago, the age of mathematics. With the advanced prosperity of mathematics in ancient Greece, the creed of the Pythagoras school "Everything is a number" fully expresses the admiration of people. However, at that time, the number only refers to a general integer. People have always avoided the irrational number or the concept of an infinite number. FamousZhino Paradox(Zeno's paradox) not only showed people's vague understanding of
number 0, returns True
The operand is any character (including infinty) that is not 0, and returns false
The operand is null and returns True
Operand is NaN, returns true
Operand is undefined, returns true
* Multiplication
One operand is Nan, and the result is Nan
Infinity * 0 = NaN
Infinity * Non 0 = Infinity or-infinity
precision of a floating point value is 17 decimal places, but its accuracy is far less than that of an integer. For example, 0.1 + 0.2 is not equal to 0.3, but 0.3000000000000004. Therefore, when making a judgment, do not use floating point numbers to sum up to determine whether it is equal to a value expected.
In javascript, the smallest value is Number. MIN_VALUE. Here we can imagine that Number is a class, while MIN_VALUE is a static variable, storing the minimum value. Similarly, the maximu
can we differentiate them? In JavaScript. if you divide a positive number by −0, the result is-Infinity. if the value is divided by + 0, the result is Infinity. the two Infinity values can be determined using ===:
The Code is as follows:
> 1/-0-Infinity> 1/+ 0Infinity> Infinity
indicates from negative infinity to positive infinity.
In the alphabetic and symbolic algorithms, auto indicates from 1 to positive infinity.
In the additive algorithm, auto indicates from 0 to positive infinity.
In the extend algorithm, auto obtains the value range of the inherited parent system. If it is a predef
In the previous article, we explained the unary operators, bitwise operators, and boolean operators in javascript operators. Today we will continue to explain the remaining operators, including multiplication operators, addition operators, equality operators, condition operators, value assignment operators, and comma operators. Let's take a closer look at these operators to help improve your understanding of javascript.
I. Multiplication Operators
1. Multiplication :*
Special rules for multipli
hopping and the frequency domain is infinitely wide, such as a square wave signal. If it is represented by a sampling signal of limited bandwidth, it is equivalent to a partial sum of compound-interest-leaf series, and this part and when recovering the original signal, there will be burrs on the non-conductive point, also known as Gibbs phenomenon.3. Why did Fourier come up with such a progression? This is the basic idea of Western philosophy and Science: Orthogonal analysis method. For example
large integer // long L = 300000000000 // can be compiled normally long L = 300000000000L; System.out.println (l); } } character char is actually an integer type, equivalent to an unsigned integer type. Floating-point types include float and doubleDouble is 8 bytes, 64 bits; float takes 4 bytes, 32 bits.Only floating-point types can be represented by scientific notation.The floating-point type is the default double type, and if you want Java to treat a f
object, and then apply the previous rule to the returned value. If the result is NaN, call the toString () method and then apply the preceding rule. The object variable is a numeric variable.
Quiz:
What is the result of performing the post-increment operation on the following types of values?
"2", "02dd", "", false, 22.5, + "",-false, + new Date ()
3. Addition Operators
The plus operator is also used for string connectors in Javascript, so the plus operator rules are divided into two situations
distance between any two points is:The entire algorithm process, though cumbersome, but the code implementation is very simple, the core code only five elements:
For (k=1;k
For (i=1;i
For (j=1;j
if (E[i][j]>e[i][k]+e[k][j])
E[I][J]=E[I][K]+E[K][J];
The basic idea of this code is that it is only allowed to go through the number 1th vertices at first, and then only the 1 and 2nd vertices are allowed to relay ... The shortest distance between any two points is allow
vertex only passes the shortest distance from the front K points. In fact, this is a "dynamic planning" of the idea, about this idea we will be in the "Aha!" The algorithm 2--the great thinking shines in a detailed discussion. The complete code for this algorithm is given below:
#include
int main ()
{
int e[10][10],k,i,j,n,m,t1,t2,t3;
int inf=99999999; Use INF (infinity abbreviation) to store a positive
to all 1s and a non-zero fraction. There are two categories of Nan:qnan (Quiet nan) and Snan (signalling Nan).AQnanis a NaN with the most significant fraction bit set. Qnan ' s propagate freely through most arithmetic. These values pops out of a operation when the are not mathematically defined.AnSnanis a NaN with the most significant fraction bit clear. It is used to signal a exception when used in operations. Snan ' can be handy to assign to uninitialized variables to trap premature usage.Sem
points, number=5 can not insert records before , number=5 existing records can no longer insert new records, number=5 after You cannot insert a new record, then the new number=5 record will not be inserted. So, how does MySQL control number=5 before, and then cannot have new records inserted (to prevent phantom reading)?The answer is to use a gap lock, at the RR level, MySQL through the gap lock can achieve lock number=5 before the Gap, Number=5 records between the Gap, number=5 after the gap,
: canonical, below normal, infinity and Non-numeric (Nan, not a number). Most numbers are normalized, meaning that the first digit of the binary tail is 1, which means you don't actually need to store it. For example, binary number 1.01101 can only be represented by. 01101-the beginning of 1 is assumed, and if it is 0, a different exponent will be used. That technique works only if the number is available in a suitable exponential range. Numbers that
Arithmetic operatorsplus : When manipulating numbers, characters, and strings, the result is different, when two characters are added to the ASCII table value, and when two strings are added together, the two strings are concatenated to form a new string.Division sign : integer when using the division sign operation, the resulting result is still an integer (fractional part omitted), and an arithmetic exception is thrown when the integer is divided by 0.Positive
the International standard IEEE 754,javascript floating point number of 64 bits, starting from the leftmost, this constitutes:
1th bit: Sign bit, 0 for integer, 1 for negative number;
2nd to 12th place: index part;
13th to 64th bit: Fractional part (valid number)
IEEE 754 stipulates that the first digit of the valid number is 1 by default, and is not guaranteed to exist in 64-bit floating-point numbers. As a result, JavaScript provides a maximum number of valid digits (13~
modulo
Infinity*0//nan
0/0//nan
Infinity/infinity//nan
Additive operator1. Addition (Turn string)Two operators are numericPerforms a conventional addition calculation.
Infinity +-infinity//nan
If one of the operands is a string
If two operators
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