Using PHP to implement a simple subtraction calculator function

Subtraction Calculator Presumably everyone has used it, this article for you to introduce how to use PHP to achieve

Calculator for small programs written in PHP base language

Requirements: Enter numbers in the input box to add, subtract, multiply, divide (html+php)

Ideas:

1 first to create input boxes for entering numbers and operators, number with the Text property of input, operator with SELELCT option property

2 Click the = number in the input box to perform the corresponding operation,

3 = number This input box can be done with the submit of input, just click on the contents of the submit form and pass it to PHP.

4 Judging the operators that are obtained from HTML for the corresponding operation

5 When the operation is complete, return the result to the table consignments (which is the value assignment to the form)

The code is as follows:

<?php header ("Content-type:text/html;charset=utf-8"); Session_Start ();?> <! DOCTYPE HTML PUBLIC "-//W3C//DTD XHTML 1.0 transitional//en" "Http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd ">