位运算判断奇偶数_按位运算做奇偶数判断

测试结果：这点差距建议忽略不计，还是用 % 比较通俗易懂

测试代码

$run_times = 100000000; // 读作 壹亿

$times = $run_times;

$start_time = microtime(true);

while (--$times) {

0 % 2;

1 % 2;

2 % 2;

1000 % 2;

1001 % 2;

100000000 % 2;

100000001 % 2;

}

$end_time = microtime(true);

$elapsed = $end_time - $start_time;

echo "% cost {$elapsed} seconds" . PHP_EOL;

$times = $run_times;

$start_time = microtime(true);

while (--$times) {

0 & 1;

1 & 1;

2 & 1;

1000 & 1;

1001 & 1;

100000000 & 1;

100000001 & 1;

}

$end_time = microtime(true);

$elapsed = $end_time - $start_time;

echo "& cost {$elapsed} seconds" . PHP_EOL;

运行5次的结果

# 1

% cost 0.92668008804321 seconds

& cost 0.91673493385315 seconds

# 2

% cost 0.94068813323975 seconds

& cost 0.91913104057312 seconds

# 3

% cost 0.93546605110168 seconds

& cost 0.91442203521729 seconds

# 4

% cost 0.91190505027771 seconds

& cost 0.90930008888245 seconds

# 5

% cost 0.93385791778564 seconds

& cost 0.9063708782196 seconds