javascript和php之间按位操作结果的差异 [英] Difference in the results of operations bitwise between javascript and php

问题描述

Javascript代码：

Javascript code:

console.log( 1 << 5 );
console.log( 1111044149 << 2 );

Javascript输出：

Javascript output:

32
149209300

PHP代码：

var_dump( 1 << 5 );
var_dump( 1111044149 << 2 );

PHP输出：

32
4444176596

为何 1111044149< ;< 2 PHP和javascript有区别吗？我正在为PHP编写一个javascript代码，一切都不那么重要，我需要PHP代码显示在javascript中获得的类似结果是完美的。

Why 1111044149 << 2 has difference between PHP and javascript? I'm writing a javascript code to PHP and everything worked less that part and I need the PHP code shows similar results obtained in javascript to be perfect.

推荐答案

JavaScript中按位运算的操作数总是被视为int32，而在PHP中则不是这样。因此，当在 1111044149 上执行左移时，这发生在JS中：

The operands of a bitwise operation in JavaScript are always treated as int32, and in PHP this is not the case. So, when performing the left shift on 1111044149, this happens in JS:

01000010001110010011000000110101 (original, 32-bit)

00001000111001001100000011010100 (left shifted 2 positions, "01" is truncated)
= 149209300

在PHP中，这些位不会被截断，因为它不被视为32位整数。

And in PHP, the bits do not get truncated because it is not treated as a 32-bit integer.

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