How many bytes are occupied by char [] and String types in Java
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In C language
1. How many bytes does this a take in char a [10] = {"China"}?
Answer: it takes up 10 bytes.
Parsing: the above code assigns a value to a
A [0] ='C', a [1] ='h', a [2] ='i', a [3] ='n', a [4] ='a', a [5] ='\ 0century] a [6] =''\ 0century force a [7] ='\ 0century law a [8] ='\ 0century month a [9] ='\ 0'
So, it takes up 10 bytes.
2. If you only refer to "China"?
A: a total of 6 bytes. China occupies 5 bytes and ends with'\ 0', accounting for 1 byte.
In the Java language
1. String s = "China"; how many bytes?
Answer: it takes up 5 bytes.
System.out.println (Charset.defaultCharset ()); / / get ide default encoding type String s = new String ("China" .getBytes ()); byte [] b = s.getBytes (); System.out.println ("" + b.length)
With the above code, you can output "China" with a byte length of 5.
2. String s = "China"; how many bytes?
A: in the case of Chinese characters, you need to consider coding.
(1) when GBK coding (ide default), each Chinese character occupies 2 bytes, then China occupies 4 bytes.
(2) when UTF-8 coding, each Chinese character occupies 3 bytes, then China occupies 6 bytes.
3. Transcoding problem: will the byte footprint become larger when GBK is converted to UTF-8? And the other way around?
/ / get UTF-8 code System.out.println (Charset.defaultCharset ()); String sporttry {s = new String ("China" .getBytes (), "GBK"); byte [] b = s.getBytes (); System.out.println ("" + b.length);} catch (UnsupportedEncodingException e) {e.printStackTrace ();}
As the above code is: UTF-8 to GBK encoding format, s length from 6 bytes to 9 bytes.
S content change: China-> trickle
Because the current encoding is UTF-8, it becomes 3 words after transcoding, occupying 9 bytes. However, the opposite goes like this:
China (gbk)? (utf-8)
The length of s has changed from 4 bytes to 4 bytes, although the length has not changed, but the text has changed. Here? Occupies 1 byte.
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