Left Shift (<<)

The left shift operator (<<) moves all bits to the left by a specified number of positions. New bits on the right are filled with 0.

Example: $5 << 2$. In binary, $5 = 101$. Shifting left by 2 positions gives $10100 = 20$. Notice that shifting left by $k$ positions multiplies the number by $2^k$. Here, $5 \times 2^2 = 20$.

Left shift is how you quickly compute powers of 2. The expression $1 << k$ gives you $2^k$. Want $2^{10}$? Write $1 << 10$. It's faster than calling a power function.