} else { print "Please input right num"; exit; } } } else { if (strpos($complex, "+")) { $real = $num[0][0]; $imaginary = 1; } else { if (strpos($complex, "-")) { $real = $num[0][0]; $imaginary = -1; } else { $real = 0; $imaginary = $num[0][0] + "0"; } } } } } else { $real = $complex + "0"; $imaginary = 0; } $return = ['real' => $real, 'imaginary' => $imaginary]; return $return; } } $complex = Complex::getInstance(); $complex->operation("input", "2+i"); $complex->operation("plus", "-3-5i");