What is the difference between float and double? - Stack Overflow
Type double, 64 bits long, has a bigger range (*10^+/-308) and 15 digits precision. Type long double is nominally 80 bits, though a given compiler/OS pairing may store it as 12-16 bytes for alignment purposes. The long double has an exponent that just ridiculously huge and should have 19 digits precision.

c - 'float' vs. 'double' precision - Stack Overflow
The reason it's called a double is because the number of bytes used to store it is double the number of a float (but this includes both the exponent and significand). The IEEE 754 standard (used by most compilers) allocates relatively more bits for the significand than the exponent (23 to 9 for float vs. 52 to 12 for double ), which is why the ...

c语言中float、double的区别和用法？ - 知乎
而double大约能精确到小数点后面的15位左右。 具体精确到几位，跟所用的编译器有关，但是各个编辑器编译器之间，也是相差不大的。 至于整数部分，float表示的整数部分的范围，就已经够大了，能表示到万亿级别，已经大到没边了。

c++ - Double precision - decimal places - Stack Overflow
On the other hand, if you print out an arbitrary double with 15 decimal places and the convert it back to a double, you won't necessarily get the same value back—you need 17 decimal places for that. And neither 15 nor 17 decimal places are enough to accurately display the exact decimal equivalent of an arbitrary double.

What exactly does Double mean in java? - Stack Overflow
A double is an IEEE754 double-precision floating point number, similar to a float but with a larger range and precision. IEEE754 single precision numbers have 32 bits (1 sign, 8 exponent and 23 mantissa bits) while double precision numbers have 64 bits (1 sign, 11 exponent and 52 mantissa bits).

How do I print a double value with full precision using cout?
A double is a floating point type, not fixed point. Do not use std::fixed as that fails to print small double as anything but 0.000...000. For large double, it prints many digits, perhaps hundreds of questionable informativeness.

Difference between long double and double in C and C++
The standard only requires that long double is at least as precise as double, so some compilers will simply treat long double as if it is the same as double. But, on most x86 chips, the 10-byte extended precision format 80-bit number is available through the CPU's floating-point unit, which provides even more precision than 64-bit double , with ...

Correct format specifier for double in printf - Stack Overflow
Format %lf is a perfectly correct printf format for double, exactly as you used it. There's nothing wrong with your code. There's nothing wrong with your code. Format %lf in printf was not supported in old (pre-C99) versions of C language, which created superficial "inconsistency" between format specifiers for double in printf and scanf .

c++ - Should I use double or float? - Stack Overflow
There are three floating point types: float, double, and long double. The type double provides at least as much precision as float, and the type long double provides at least as much precision as double. So, all three can be the same size in memory. Presence of an FPU.

Difference between decimal, float and double in .NET?
Double: It is also a floating binary point type variable with double precision and 64 bits size(15-17 significant figures). Double are probably the most generally used data type for real values, except for financial applications and places where high accuracy is desired. Decimal: It is a floating decimal point type variable.