How PHP handles high-precision calculation functions

This article mainly shares with you how PHP handles high-precision calculation functions. It mainly shares with you two methods of graphing. I hope it can help you.

Method 1:

PHP provides a binary calculator (Binary Calculator) for arbitrary precision mathematical calculations, which supports numbers of any size and precision, described in string form

bcadd — Addition
bccomp — Comparison
bcp — Division
bcmod — Find the remainder
bcmul — Multiplication
bcpow — Power
bcpowmod — Power first and then find the remainder
bcscale — Set the decimal place precision for all functions
bcsqrt — Find the square root
bcsub — Subtraction

Method 2:

I encountered a strange problem recently, the mall paid through WeChat The order price is often one penny less. After investigation, it is caused by the accuracy of PHP floating point operations.

It is caused by the accuracy of PHP floating point operations. Brother Niao's Bolg has a detailed explanation. http://www.laruence.com/2013/03/26/2884.html,
When decimals are represented in binary, 0.58 is an infinitely long value for binary.

The binary representation of 0.58 is basically (52 bits) is: 0010100011110101110000101000111101011100001010001111

The binary representation of 0.57 is basically (52 bits): 001000111101011100001010001111010111000 0101000111101

Convert to floating point number (64-bit double precision)

0.58 - > 0.57999999999999996

0.57 -> 0.56999999999999995

0.58*100 = 57.999999999 (int)(0.58*100) = 57

Solution:

(int)((0.58*1000)/10) = 58

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