string 从matlab中的字符串中提取前4个字母
声明：本页面是StackOverFlow热门问题的中英对照翻译，遵循CC BY-SA 4.0协议，如果您需要使用它，必须同样遵循CC BY-SA许可，注明原文地址和作者信息，同时你必须将它归于原作者（不是我）：StackOverFlow
原文地址: http://stackoverflow.com/questions/5545963/
Warning: these are provided under cc-by-sa 4.0 license. You are free to use/share it, But you must attribute it to the original authors (not me):
StackOverFlow
extract first 4 letters from a string in matlab
提问by Dilip
How can I extract the first 4 or the middle 4 or last four letters of a string example: when the string reads 01 ED 01 F9 81 C6?
如何提取字符串示例的前 4 个或中间 4 个或后四个字母：当字符串读取 01 ED 01 F9 81 C6 时？
回答by trolle3000
A string is treated like a vector of chars. Try this:
字符串被视为字符向量。尝试这个：
>> string = '01 ED 01 F9 81 C6';
>> string(1:5), string(6:11), string(12:17)
ans =
01 ED
ans =
01 F9
ans =
81 C6
stringin this example is a variable not a method. string(1)returns the first char in the array (or vector) called string.
string在这个例子中是一个变量而不是一个方法。string(1)返回名为 的数组（或向量）中的第一个字符string。
回答by b3.
If you want only the non-whitespace characters you could use the ISSPACEfunction to remove the whitespace and then character array indexing to access the characters:
如果您只想要非空白字符，则可以使用ISSPACE函数删除空白，然后使用字符数组索引来访问字符：
>> s = '01 ED 01 F9 81 C6'; >> s = s(~isspace(s)) s = 01ED01F981C6 >> s(1:4) ans = 01ED >> s(5:8) ans = 01F9 >> s(9:end) ans = 81C6
You can expand this to process multiple lines of a character array using RESHAPEto transform the result of the space removal back to a 2D-array and then referencing the extra dimension:
您可以将其扩展为使用RESHAPE处理字符数组的多行，将空间移除的结果转换回二维数组，然后引用额外的维度：
s = ['01 ED 01 F9 81 C6'; 'F8 CA DD 04 44 3B'] s = 01 ED 01 F9 81 C6 F8 CA DD 04 44 3B >> s = reshape(s(~isspace(s)), size(s, 1), 12) s = 01ED01F981C6 F8CADD04443B >> s(:,1:4) ans = 01ED F8CA >> s(:,5:8) ans = 01F9 DD04 >> s(:,9:end) ans = 81C6 443B
回答by Richie Cotton
As trolle3000 and b3 mentioned, you use brackets containing indices to extract subsets of the string.
正如 trolle3000 和 b3 所提到的，您使用包含索引的括号来提取字符串的子集。
To answer the additional question of how you work on the string, I suggest that you split the string at each space, and convert from hexadecimal to decimal numbers.
要回答有关如何处理字符串的附加问题，我建议您在每个空格处拆分字符串，然后将十六进制数转换为十进制数。
s = '01 ED 01 F9 81 C6';
hex2dec(regexp(s, ' ', 'split'))
ans =
1
237
1
249
129
198
