What is the function of '<<=' operator in C?

Question

Which is the best practice for variable declaration within the function ? Or is it vary from one language to other one ?

Answer 1

The operator <<= is used to shift the bits of variable (mentioned at the left side) by the number (mentioned at the right side).
For example:
int a = 1;
int b = 3;
a <<= b;
printf("%d", a);

Output will be = 8 because value of variable a is left shifted by 3.