user-0 提问: 为什么％ld也显示不出来长数据

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user: user-0
content: 引用 6 楼 赵4老师的回复:常量也有类型！ C++ Integer Constants Integer constants are constant data elements that have no fractional parts or exponents. They always begin with a digit. You can specify integer constants in decimal, octal, or hexadecimal form. They can specify signed or unsigned types and long or short types.  Syntax  integer-constant :  decimal-constant integer-suffixopt octal-constant integer-suffixopt hexadecimal-constant integer-suffixopt 'c-char-sequence'  decimal-constant :  nonzero-digit decimal-constant digit  octal-constant :  0 octal-constant octal-digit  hexadecimal-constant :  0x hexadecimal-digit 0X hexadecimal-digit hexadecimal-constant hexadecimal-digit  nonzero-digit : one of  1 2 3 4 5 6 7 8 9  octal-digit : one of  0 1 2 3 4 5 6 7  hexadecimal-digit : one of  0 1 2 3 4 5 6 7 8 9 a b c d e f A B C D E F  integer-suffix :  unsigned-suffix long-suffixopt long-suffix unsigned-suffixopt  unsigned-suffix : one of  u U  long-suffix : one of  l L  64-bit integer-suffix :  i64  To specify integer constants using octal or hexadecimal notation, use a prefix that denotes the base. To specify an integer constant of a given integral type, use a suffix that denotes the type.  To specify a decimal constant, begin the specification with a nonzero digit. For example:  int i = 157;   // Decimal constant int j = 0198;  // Not a decimal number; erroneous octal constant int k = 0365;  // Leading zero specifies octal constant, not decimal  To specify an octal constant, begin the specification with 0, followed by a sequence of digits in the range 0 through 7. The digits 8 and 9 are errors in specifying an octal constant. For example:  int i = 0377;   // Octal constant int j = 0397;   // Error: 9 is not an octal digit  To specify a hexadecimal constant, begin the specification with 0x or 0X (the case of the “x” does not matter), followed by a sequence of digits in the range 0 through 9 and a (or A) through f (or F). Hexadecimal digits a (or A) through f (or F) represent values in the range 10 through 15. For example:  int i = 0x3fff;   // Hexadecimal constant int j = 0X3FFF;   // Equal to i  To specify an unsigned type, use either the u or U suffix. To specify a long type, use either the l or L suffix. For example:  unsigned uVal = 328u;             // Unsigned value long lVal = 0x7FFFFFL;            // Long value specified                                    //  as hex constant unsigned long ulVal = 0776745ul;  // Unsigned long value 谢谢大佬，我才入门，见笑了

user: user-1
content: 数据越界了，越界的数据会被截断，高于long的内容会去掉（二进制形式）

user: user-2
content: 常量也有类型！ C++ Integer Constants Integer constants are constant data elements that have no fractional parts or exponents. They always begin with a digit. You can specify integer constants in decimal, octal, or hexadecimal form. They can specify signed or unsigned types and long or short types.  Syntax  integer-constant :  decimal-constant integer-suffixopt octal-constant integer-suffixopt hexadecimal-constant integer-suffixopt 'c-char-sequence'  decimal-constant :  nonzero-digit decimal-constant digit  octal-constant :  0 octal-constant octal-digit  hexadecimal-constant :  0x hexadecimal-digit 0X hexadecimal-digit hexadecimal-constant hexadecimal-digit  nonzero-digit : one of  1 2 3 4 5 6 7 8 9  octal-digit : one of  0 1 2 3 4 5 6 7  hexadecimal-digit : one of  0 1 2 3 4 5 6 7 8 9 a b c d e f A B C D E F  integer-suffix :  unsigned-suffix long-suffixopt long-suffix unsigned-suffixopt  unsigned-suffix : one of  u U  long-suffix : one of  l L  64-bit integer-suffix :  i64  To specify integer constants using octal or hexadecimal notation, use a prefix that denotes the base. To specify an integer constant of a given integral type, use a suffix that denotes the type.  To specify a decimal constant, begin the specification with a nonzero digit. For example:  int i = 157;   // Decimal constant int j = 0198;  // Not a decimal number; erroneous octal constant int k = 0365;  // Leading zero specifies octal constant, not decimal  To specify an octal constant, begin the specification with 0, followed by a sequence of digits in the range 0 through 7. The digits 8 and 9 are errors in specifying an octal constant. For example:  int i = 0377;   // Octal constant int j = 0397;   // Error: 9 is not an octal digit  To specify a hexadecimal constant, begin the specification with 0x or 0X (the case of the “x” does not matter), followed by a sequence of digits in the range 0 through 9 and a (or A) through f (or F). Hexadecimal digits a (or A) through f (or F) represent values in the range 10 through 15. For example:  int i = 0x3fff;   // Hexadecimal constant int j = 0X3FFF;   // Equal to i  To specify an unsigned type, use either the u or U suffix. To specify a long type, use either the l or L suffix. For example:  unsigned uVal = 328u;             // Unsigned value long lVal = 0x7FFFFFL;            // Long value specified                                    //  as hex constant unsigned long ulVal = 0776745ul;  // Unsigned long value

user: user-3
content: %d %x %o对应int %ld %lx %lo对应long int %lld %llx %llo对应long long int %u 对应 unsigned int %lu 对应 unsigned long int %llu 对应 unsigned long long int long变量的范围和int一样，容纳的范围是-20亿 到 20亿 左右 你这个超范围了 long long c = 9999999999; printf("%lld", c ); 就行了

user: user-4

user: user-5
content: 这个很好解释 long类型表示的范围是-2147483648～+2141483647,共有4294967296个数 你初始值为9999999999明显超过了范围，所以编译器帮你做了9999999999 mod 4294967296 = 1410065407 如果你想显示9999999999，只需将long改为long long即可，当然printf中也要改成%lld  #include <stdio.h>  int main(void) {    long long c = 9999999999;    printf("%lld\n", c);    return 0; }

user: user-4
content: sizeof一下，看看你的系统上long的字节大小