PHP uses super long (oversized) number operations to prevent numbers from being displayed in scientific notation, php counting

PHP uses super long (oversized) number operations to prevent numbers from being displayed in scientific notation, php counting_PHP tutorial

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Release： 2016-07-12 08:55:22

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PHP uses super long (very large) number operations to prevent numbers from being displayed in scientific notation, php counting

This article describes an example of PHP using super long (very large) number operations to prevent numbers from being displayed in scientific notation. A method of displaying numbers in scientific notation. Share it with everyone for your reference, the details are as follows:

PHP will make errors when calculating large numerical operations. When the number is too large, the value will become scientific notation. So how to perform large numerical operations in PHP, including addition, subtraction, multiplication, division, power operations, square roots, and modulo operations?

To solve the problem of scientific notation, just add a pair of quotation marks when assigning values.

For example:

<&#63;php
$n = '22222222222222222222222222220';
echo $n;
&#63;>

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Without quotation marks, it displays 2.2222222222222E 28. With quotation marks, it displays 22222222222222222222222222220

Extremely large numerical operations, including addition, subtraction, multiplication and division, power operations, square roots, and modular operations.

Use PHP’s bcmath function to create a custom function, the code is as follows,

<&#63;php
function calc($m,$n,$x){
  $errors=array(
    '被除数不能为零',
    '负数没有平方根'
  );
  switch($x){
    case 'add':
      $t=bcadd($m,$n);
      break;
    case 'sub':
      $t=bcsub($m,$n);
      break;
    case 'mul':
      $t=bcmul($m,$n);
      break;
    case 'div':
      if($n!=0){
        $t=bcdiv($m,$n);
      }else{
        return $errors[0];
      }
      break;
    case 'pow':
      $t=bcpow($m,$n);
      break;
    case 'mod':
      if($n!=0){
        $t=bcmod($m,$n);
      }else{
        return $errors[0];
      }
      break;
    case 'sqrt':
      if($m>=0){
        $t=bcsqrt($m);
      }else{
        return $errors[1];
      }
      break;
  }
  $t=preg_replace("/\..*0+$/",'',$t);
  return $t;
}
/*用法举例*/
echo calc('11111111111111111111111111111111110','10','add');
&#63;>

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Usage:

calc(parameter 1 parameter 2, parameter 3);
Parameter 3 specifies the operation method: add, sub, mul, div, pow, mod, sqrt to find the arithmetic square root
Addition, subtraction and division: Parameter 1 Add/Subtract/Multiply/Divide Parameter 2
Power: parameter 1 raised to the power of parameter 2.
Modulo: the remainder obtained by dividing parameter 1 by parameter 2.
Arithmetic square root: Find the arithmetic square root of parameter 1. Parameter 2 has no effect, but cannot be omitted.

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I hope this article will be helpful to everyone in PHP programming.

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