![js中有["1","2","3","4"]这样一个string，怎么把它变成array](/aiimages/js%E4%B8%AD%E6%9C%89%5B%26quot%3B1%26quot%3B%2C%26quot%3B2%26quot%3B%2C%26quot%3B3%26quot%3B%2C%26quot%3B4%26quot%3B%5D%E8%BF%99%E6%A0%B7%E4%B8%80%E4%B8%AAstring%EF%BC%8C%E6%80%8E%E4%B9%88%E6%8A%8A%E5%AE%83%E5%8F%98%E6%88%90array.png)
轴用h，20h7=20（0，-0.021）
孔的话应该用H，即20H7，公差（+0.021,0）
孔的公差表 (ISO)
≥< B10C9D8E7E8F7G7H6H7H8JS7K7M7N7P7R7S7T7
—318085342428161261014±50-2-4-6-10-14—
1406020141462000-10-12-14-16-20-24
36188100483238221681218±630-4-8-11-15—
14070302020104000-9-12-16-20-23-27
610208116624047282091522±750-4-9-13-17—
15080402525135000-10-15-19-24-28-32
10142001387750593424111827±960-5-11-16-21—
141815095503232166000-12-18-23-29-34-39
18242441629861734128132133±1060-7-14-20-27—
2430160110654040207000-15-21-28-35-41-48-33
-54
304027018211975895034162539±1270-8-17-25-34-39
170120805050259000-18-25-33-42-50-59-64
4050280192 -45
180130 -70
5065310214146901066040193046±1590-9-21-30-42-55
19014010060603010000-21-30-39-51-60-72-85
6580320224 -32-48-64
200150 -62-78-94
801003602571741071257147223554±17100-10-24-38-58-78
22017012072723612000-25-35-45-59-73-93-113
100120380267 -41-66-91
240180 -76-101-126
1201404203002081251488354254063±20120-12-28-48-77-107
26020014585854314000-28-40-52-68-88-117-147
140160440310 -50-85-119
280210 -90-125-159
160180470330 -53-93-131
310230 -93-133-171
1802005253552421461729661294672±23130-14-33-60-105-149
3402401701001005015000-33-46-60-79-106-151-195
200225565375 -63-113-163
380260 -109-159-209
225250605395 -67-123-179
420280 -113-169-225
25028069043027116219110869325281±26160-80-36-74-138-198
4803001901101105617000-36-52-88-126-190-250
280315750460 -78-150-220
540330 -130-202-272
31535583050029918221411975365789±28170-16-41-87-169-247
6003602101251256218000-40-57-73-98-144-226-304
355400910540 -93-187-273
680400 -150-244-330
400450101059532719823213183406397±31180-17-45-103-209-307
76044023013513513520000-45-63-80-108-166-272-370
4505001090635 -109-229-337
840480 -172-292-400
