In Julia, the this keyword refers to the current object being operated on, while the that keyword is not a reserved word. However, you can assign values to variables using either the = symbol or the x .= y syntax to assign a value to an array. Here are examples of both:
Using the = symbol:
# Assigning a value to a variable
x = 5
println(x) # Output: 5
# Assigning a value to an array
y = [1, 2, 3]
y[1] = 4
println(y) # Output: [4, 2, 3]
Using the .= syntax:
# Assigning a value to an array
x = [1, 2, 3]
y = [4, 5, 6]
x .= y
println(x) # Output: [4, 5, 6]
Note that the .= syntax is used to assign the entire array y to the corresponding elements of x. If = had been used instead, x would have just been assigned the value of y without copying elements.