double sqrt(
num x
)

Converts x to a double and returns the positive square root of the value.

Returns -0.0 if x is -0.0, and NaN if x is otherwise negative or NaN.

Source

/**
 * Converts [x] to a double and returns the positive square root of the value.
 *
 * Returns -0.0 if [x] is -0.0, and NaN if [x] is otherwise negative or NaN.
 */
external double sqrt(num x);