英文:
Bitshifting: Can someone explain what this code does?
问题
所以，我正在阅读一本关于Go语言的书（《Go的道路》作者：Ivo Balbaert），其中有一个代码示例：
const hardEight = (1 << 100) >> 97
由于我在这台机器上没有安装Go，所以我决定将其翻译为PHP以查看结果（通过http://writecodeonline.com/php/，因为我在这台机器上也没有安装PHP）：
echo (1 << 100) >> 97;
上述代码的结果是8....嗯？所以我决定写一个从0到100的for循环来查看结果：
for($i = 0; $i <= 100; $i++){
echo $i . ": ";
echo ($i << 100) >> 97;
echo "<br>";
}
然而，结果是：
0: 0
1: 8
2: 16
3: 24
4: 32
5: 40
6: 48
7: 56
8: 64
9: 72
10: 80
11: 88
12: 96
13: 104
14: 112
15: 120
16: 128
17: 136
18: 144
19: 152
20: 160
21: 168
22: 176
23: 184
24: 192
25: 200
26: 208
27: 216
28: 224
29: 232
30: 240
31: 248
32: 256
33: 264
34: 272
35: 280
36: 288
37: 296
38: 304
39: 312
40: 320
41: 328
42: 336
43: 344
44: 352
45: 360
46: 368
47: 376
48: 384
49: 392
50: 400
51: 408
52: 416
53: 424
54: 432
55: 440
56: 448
57: 456
58: 464
59: 472
60: 480
61: 488
62: 496
63: 504
64: 512
65: 520
66: 528
67: 536
68: 544
69: 552
70: 560
71: 568
72: 576
73: 584
74: 592
75: 600
76: 608
77: 616
78: 624
79: 632
80: 640
81: 648
82: 656
83: 664
84: 672
85: 680
86: 688
87: 696
88: 704
89: 712
90: 720
91: 728
92: 736
93: 744
94: 752
95: 760
96: 768
97: 776
98: 784
99: 792
100: 800
有人能解释一下这段代码发生了什么吗？我知道这是位移操作，但我不太理解位移操作的原理，无法确定其中发生了什么。谢谢 
英文:
So, I'm reading a book on Go (The Way to Go by Ivo Balbaert), and in it there is a code sample:
const hardEight = (1 << 100) >> 97
Since I don't have Go installed on this machine, I decided to translate it to PHP to see the results (via http://writecodeonline.com/php/ since I don't have PHP installed on this machine either):
echo (1 << 100) >> 97;
The result for the above is 8....huh? So I wrote decided ok, lets write a for-loop from 0 to 100 and see the results:
for($i = 0; $i <= 100; $i++){
echo $i . ": ";
echo ($i << 100) >> 97;
echo "<br>";
}
However, the results are:
0: 0
1: 8
2: 16
3: 24
4: 32
5: 40
6: 48
7: 56
8: 64
9: 72
10: 80
11: 88
12: 96
13: 104
14: 112
15: 120
16: 128
17: 136
18: 144
19: 152
20: 160
21: 168
22: 176
23: 184
24: 192
25: 200
26: 208
27: 216
28: 224
29: 232
30: 240
31: 248
32: 256
33: 264
34: 272
35: 280
36: 288
37: 296
38: 304
39: 312
40: 320
41: 328
42: 336
43: 344
44: 352
45: 360
46: 368
47: 376
48: 384
49: 392
50: 400
51: 408
52: 416
53: 424
54: 432
55: 440
56: 448
57: 456
58: 464
59: 472
60: 480
61: 488
62: 496
63: 504
64: 512
65: 520
66: 528
67: 536
68: 544
69: 552
70: 560
71: 568
72: 576
73: 584
74: 592
75: 600
76: 608
77: 616
78: 624
79: 632
80: 640
81: 648
82: 656
83: 664
84: 672
85: 680
86: 688
87: 696
88: 704
89: 712
90: 720
91: 728
92: 736
93: 744
94: 752
95: 760
96: 768
97: 776
98: 784
99: 792
100: 800
Can someone explain to me what is going on with the snippet? I know its bitshifting, but I don't understand bitshifting well enough to discern what is going on there. Thank you
答案1
得分: 2
以1为例（你循环遍历0-100，但对于所有数字都是相同的原则）
从括号内开始：
(1 << 100)
将数字1左移100位。这给出了1后面跟着100个零。然后，这个非常大的数字（称为谷歌）向右移动97位，得到：
1000
这是十进制数8的二进制表示。对于其他数字，它们首先被转换为二进制（所以2变成10，3变成11等），然后应用计算。
英文:
Using 1 as an example(you loop through 0-100 but its the same principal for all)
Starting with what is inside the brackets:
(1 << 100)
will do a left shift on the number 1 by 100 places. this gives you 1 followed by 100 zeros. then, this really large number(known as a googol) gets shifted right by 97 which leaves you with:
1000
which is the binary representation of the decimal number 8. For the other numbers, they are converted to binary first(so 2 becomes 10, 3 becomes 11 etc..) and the calculation is applied.
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