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  1. <?php
  2.  
  3. $string = "-2.43+3.62/2.1*9.02";
  4.  
  5. function calculate($string)
  6. {
  7. 	$reg = '/(\-*\d+([.,]\d+)*)|(\*)|(\/)|(\+)|(\-)/';
  8.  
  9. 	//Разбиваем выражение на данные и операторы
  10. 	if (preg_match_all($reg, $string, $matches)) {
  11. 		foreach($matches[0] as $position => $value) {
  12.  
  13. 			//Определяем приоритет действий
  14. 			switch($value) {
  15. 				case '*':
  16. 				$steps[1][$position] = $value;
  17. 				break;
  18. 				case '/':
  19. 				$steps[1][$position] = $value;
  20. 				break;
  21. 				case '+':
  22. 				$steps[2][$position] = $value;
  23. 				break;
  24. 				case '-':
  25. 				$steps[2][$position] = $value;
  26. 				break;
  27. 			}
  28. 		}
  29.  
  30. 		ksort($steps);
  31.  
  32.  
  33. 		//Считаем первое действие...
  34. 		foreach($steps as $step) {
  35. 			foreach($step as $position => $operator) {
  36. 				switch($operator) {
  37. 					case '*':
  38. 						$exp = $matches[0][$position - 1] * $matches[0][$position +1];
  39. 						break;
  40. 					case '/':
  41. 						$exp = $matches[0][$position - 1] / $matches[0][$position +1];
  42. 						break;
  43. 					case '+':
  44. 						$exp = $matches[0][$position - 1] + $matches[0][$position +1];
  45. 						break;
  46. 					case '-':
  47. 						$exp = $matches[0][$position - 1] - $matches[0][$position +1];
  48. 						break;
  49. 				}
  50.  
  51.  
  52. 				//Получаем новое выражение с новыми данными
  53. 				$newMatches = [];
  54.  
  55. 				foreach($matches[0] as $key => $value) {
  56. 					if($key == $position - 1 or $key == $position or $key == $position + 1) {
  57. 						if ($key == $position) {
  58. 							$newMatches[] = $exp;
  59. 						}
  60.  
  61. 						continue;
  62. 					}
  63.  
  64. 					$newMatches[] = $value;
  65. 				}
  66.  
  67. 				$newString = '';
  68.  
  69. 				foreach($newMatches as $value) {
  70. 					$newString .=  $value;
  71. 				}
  72.  
  73. 				//Рекурсивно повторяем вычисление до тех пор пока не получим единственное значение т.е. ответ
  74. 				if (count($newMatches) != 1) {
  75. 					return calculate($newString);
  76. 				} else {
  77. 					return $newMatches[0];
  78. 				}
  79.  
  80. 				break;
  81. 			}
  82. 		}
  83. 	}
  84. }
  85.  
  86. var_dump(calculate($string));
Success #stdin #stdout 0s 52488KB
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float(13.118761904762)
https://ideone.com/JibpcY
language:
PHP (php 7.3.5)
created:
8 years ago
visibility:
public

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