The data system of type 1.double reserves six decimal places by default, and the system will change to double type by default no matter what type is calculated.

(int) Formula A+B/B is converted int) a+b/b int first.) The result of A+B/B integer is 5, and B/B =1.0000000, so 5+ 1.0000000 = 6.000000.

2.x<& lt 1 is to convert X into binary form and then shift all bits to the left 1 bit. The output format is %o, which is octal, so just convert the result into octal output.

Char x=040 means 40 in octal (32 in decimal), 00 10000 in binary, and 0 100000 after shifting, which is equivalent to 32*2=64 in decimal and100 in octal (PS: 6540).