赋值运算符 #

x = 10
name = "Julia"
arr = [1, 2, 3]

x::Int = 10
y::Float64 = 3.14
name::String = "Julia"

a, b, c = 1, 2, 3
x, y = [10, 20]
first, second = (1, 2)

a = b = c = 0
x = y = z = 100

x = 10
x += 5
x -= 3
x *= 2
x /= 4
x ÷= 2
x ^= 2
x %= 10

x = 0b1010
x &= 0b1100
x |= 0b0011
x ⊻= 0b1111
x <<= 2
x >>= 1

arr = [1, 2, 3, 4, 5]
arr[1] = 10
arr[end] = 50

arr = [1, 2, 3, 4, 5]
arr[1:3] = [10, 20, 30]
arr[2:2:end] .= 0

arr = [1, 2, 3, 4, 5]
arr .+= 1
arr .*= 2
arr .^= 2

d = Dict{String, Int}()
d["a"] = 1
d["b"] = 2

d = Dict("a" => 1, "b" => 2)
d["a"] += 10
d["b"] *= 2

mutable struct Point
    x::Float64
    y::Float64
end

p = Point(1.0, 2.0)
p.x = 10.0
p.y += 5.0

struct ImmutablePoint
    x::Float64
    y::Float64
end

p = ImmutablePoint(1.0, 2.0)
p.x = 10.0

t = (1, 2, 3)
a, b, c = t

arr = [10, 20, 30]
x, y, z = arr

nt = (a=1, b=2, c=3)
(; a, b, c) = nt

t = (1, 2, 3, 4, 5)
a, _, c = t
first, _, _, _, last = t

mutable struct Counter
    value::Int
end

function increment!(c::Counter, delta::Int=1)
    c.value += delta
    return c.value
end

counter = Counter(0)
increment!(counter)
increment!(counter, 5)

function accumulator()
    total = 0
    function add(value)
        total += value
        return total
    end
    return add
end

acc = accumulator()
acc(10)
acc(5)
acc(3)

function swap!(a, b)
    a, b = b, a
    return a, b
end

x, y = 1, 2
x, y = swap!(x, y)