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public class Test {
public static void main (String[]args) {
int a = 10;//int ´ú±íÕûÐÍ
int b = 5;
System.out.println("aµÄÖµÊÇ:"+a);
System.out.println("bµÄÖµÊÇ:"+b);
}
}
×¢:ÕûÐÍÔÚÄÚ´æÖÐÕ¼ÓÃËĸö×Ö½Ú,²»¹ÜÊÇ32λ»¹ÊÇ64λ,ºÍ²Ù×÷ϵͳûÓйØϵ,Ò»¸ö×Ö½Ú=°Ë¸öbitλ,ËùÒÔÕûÐÍÔÚÄÚ´æÖÐÕ¼ÈýÊ®¶þ¸öbitλ,Ò»¸öbitλ´ú±íÒ»¸ö¶þ½øÖÆÊý×Ö,µÚÒ»¸öbitλ´ú±íµÄÊÇ·ûºÅλ,ºóÃæµÄÈýʮһ¸öbitλ´ú±íÊýֵλ,×ܹ²ÓÐ2^31 ÖÖ״̬,ÕýÊýÓÐ2^31-1 ÖÖ¿ÉÄÜ,¸ºÊýµÄ·¶Î§ÊÇ-2^31 ¡ª¡ª 1,ËùÒÔÎÒÃÇ¿ÉÒÔÇó³öÕûÐεÄÈ¡Öµ·¶Î§:-231-231-1
public class TestB {
public static void main(String[] args) {
int a =10;
System.out.println(Integer.MAX_VALUE);
System.out.println(Integer.MIN_VALUE);
}
}
ÕâÀïÎÒÃÇ¿ÉÒÔÓÃintµÄ°ü×°ÀàIntegerÀ´ÑéËãÈ¡Öµ·¶Î§½á¹û
×¢:¢ÙÕûÐ͵Ä×î´óÖµ+1¾Í±ä³ÉÁË×îСֵ,Ï൱ÓÚÒ»¸öÔ²Ò»ÑùÔÚһֱѻ·
public class TestC {
public static void main(String[] args) {
long a = 10L;
long b = 5L;
System.out.println("aµÄÖµÊÇ:"+a);
System.out.println("bµÄÖµÊÇ:"+b);
}
}
×¢Òâ:³¤ÕûÐÍÔÚJavaÖÐÕ¼°Ë¸ö×Ö½Ú,64¸öbitλ,Ò»¸ö·ûºÅλ,63¸öÊýֵλ,ͬÑùµÄ¼ÆËã·½·¨,ËüµÄÈ¡Öµ·¶Î§ÊÇ:-263-263-1
public class TestD {
public static void main(String[]args) {
long a = 10L;
System.out.println("×î´óÖµ:"+Long.MAX_VALUE);//¡°+¡±ÊÇÆ´½ÓµÄÒâ˼
System.out.println("×îСֵ:"+Long.MIN_VALUE);
}
}
ÕâÀïÎÒÃÇÒ²¿ÉÒÔÓÃlongµÄ°ü×°ÀàLongÀ´ÑéÖ¤
public class TestH {
public static void main (String[]args) {
short a = 2;
short b = 4;
System.out.println(a);
System.out.println(b);
}
}
¶ÌÕûÐÍÕ¼Á½¸ö×Ö½Ú,È¡Öµ·¶Î§Ò²¾ÍÊÇ-2^ 16¡ª¡ª2^15-1
ͬÑùµÄÎÒÃÇÒ²¿ÉÒÔÓÃshortµÄ°ü×°ÀàShortÀ´ÑéÖ¤:
public class TestI {
public static void main(String[]args) {
short a = 10;
System.out.println("×î´óÖµ:"+Short.MAX_VALUE);
System.out.println("×îСֵ:"+Short.MIN_VALUE);
}
}
public class TestJ {
public static void main(String[]args) {
float f = 11.5f; //СÊýĬÈÏΪÊÇË«¾«¶È,ËùÒÔÒª¼ÓÒ»¸öf
float f1= 6.3f;
System.out.println(f);
System.out.println(f1);
}
}
×¢:µ¥¾«¶È¸¡µãÐÍÕ¼Ëĸö×Ö½Ú,ÎÒÃÇͬÑù¿ÉÒÔ¼ÆËã³öËüµÄÈ¡Öµ·¶Î§Îª-231-231-1¡£Ð¡ÊýĬÈÏΪÊÇË«¾«¶ÈÀàÐÍ,ËùÒÔÔÚ¶¨ÒåµÄʱºòÐèÒªÔÚºóÃæ¼ÓÒ»¸ö"f",ÕâÒ²ÌåÏÖÁËjavaµÄ°²È«ÐÔ
public class TestK {
public static void main(String[]args) {
float f = 1.6f;
System.out.println(Float.MAX_VALUE);
System.out.println(Float.MIN_VALUE);
}
}
ÎÒÃÇͬÑù¿ÉÒÔÓÃfloatµÄ°ü×°ÀàFloatÀ´ÑéÖ¤
public class TestO {
public static void main(String[]args) {
double d = 11.5;
double d1 = 14.73;
System.out.println(d);
System.out.println(d1);
}
}
×¢:doubleÕ¼°Ë¸ö×Ö½Ú,ͬÑù¿ÉÒÔÓÃdoubleµÄ°ü×°ÀàDoubleÀ´¼ÆËãÈ¡Öµ·¶Î§¡£Ö»ÒªÊÇСÊýĬÈ϶¼ÊÇË«¾«¶ÈÀàÐÍ,ËùÒÔд³ÌÐòÓÐСÊýµÄʱºò½¨Ò鶼ÓÃdouble,µ±½øÐÐÁ½¸öÕûÊýÏà³ý½á¹ûÊÇСÊýµÄʱºò,ÐèÒª°ÑÆäÖÐÒ»¸öÕûÊý¶¨ÒåΪdoubleÀàÐÍ,±ÈÈç double d = 1.0;
public class TestP {
public static void main(String[]args) {
double d = 1.6;
System.out.println(Double.MAX_VALUE);
System.out.println(Double.MIN_VALUE);
}
}
public class TestQ {
public static void main(String[]args) {
char ch = 'A';//¿ÉÒÔÊÇÒ»¸öºº×Ö,ºº×ÖÒ²Õ¼Á½¸ö×Ö½Ú,Ò²¿ÉÒÔÊÇÊý×Ö,´òÓ¡³öÀ´µÄ½«»áÊÇÔÚUnicodeÂëÖжÔÓ¦µÄ·ûºÅ
System.out.println(ch);
}
}
×Ö·ûÊý¾ÝÀàÐÍÕ¼Á½¸ö×Ö½Ú,²»Í¬µÄÊÇÕâÀï²»¿ÉÓÃcharµÄ°ü×°ÀàCharacter¼ÆËãËüµÄÈ¡Öµ·¶Î§,ÒòΪËüµÄÈ¡Öµ¶ÔÓ¦µÄÊÇUnicodeÂëÖеķûºÅ
public class TestR {
public static void main(String[]args) {
byte a = 102;
byte b = 1;
byte c = (byte)(a+b);//СÓÚËĸö×Ö½ÚµÄÀàÐͼÆËãʱ»áÌáÉýΪÕûÐͼÆËã,ËùÒÔÐèҪǿÖÆת»»Îª×Ö½ÚÀàÐÍ
System.out.println(c);
}
}
×Ö½ÚÀàÐÍÕ¼1¸ö×Ö½Ú,¼ÆËã³õÈ¡Öµ·¶Î§Îª-128¡ª¡ª+127,ÐèҪעÒâµÄÊÇ,СÓÚËĸö×Ö½ÚµÄÀàÐÍÔÚ½øÐмÆËãʱ»áÕûÐÍÌáÉý,ËùÒÔÐèҪǿÖÆת»»Îª×Ö½ÚÐÍ
public class TestS {
public static void main (String[] args) {
byte a = 12;
System.out.println(Byte.MAX_VALUE);
System.out.println(Byte.MIN_VALUE);
}
}
ͬÑù¿ÉÒÔÓÃbyteµÄ°ü×°ÀàByteÑéÖ¤
8.²¼¶ûÀàÐÍ
public class TestT {
public static void main(String[]args) {
boolean flg = false;
System.out.println(flg);
}
}
²¼¶ûÀàÐÍÔÚjavaÖÐûÓÐÃ÷È·´óС,²¢ÇÒËüÖ»ÓÐÁ½¸öÈ¡Öµ,true/false,javaÖеÄÕæ/¼ÙÖ»ÓÐtrue/false,ûÓÐËùνµÄ0ÊǼÙ,·Ç0ÊÇÕæ¡£²¼¶ûÀàÐͶÔÓ¦µÄ°ü×°ÀàÊÇBoolean
³ýÈ¥ÒÔÉÏÕâ°Ë´ó»ù±¾Êý¾ÝÀàÐÍ,ÔÚJavaÖл¹ÓÐÒ»ÖÖ½ÐÒýÓÃÊý¾ÝÀàÐÍ,Èç:Àà String Êý×é,³éÏóÀà ½Ó¿Ú Ã¶¾ÙµÈµÈ,ÏÂÃæÎÒÃÇÔÙÀ´ÈÏʶһÏÂString
×Ö·û´®Êý¾ÝÀàÐÍ:
public class TestU {
public static void main(String[]args) {
String str ="hello";//×Ö·û´®ÓÃË«ÒýºÅ
String str1 = "hello"+"world";
System.out.println(str);
System.out.println(str1);//ÓÃ"+"¿ÉÒÔ°ÑÁ½¸ö×Ö·û´®Æ´½ÓÆðÀ´,ÈÎÒâÊý¾ÝÀàÐͺÍ×Ö·û´®Æ´½Óºó¶¼ÊÇ×Ö·û´®
}
}
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¢Ù:×ÖÃæ³£Á¿:Ïñ10,"abc"ÕâÖÖ
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