An assignment simply stores a value in a variable and has the form:
<variable> = <expression>;
An expression can be a simple value but can also be more complicated, so, rather than assigning a value to a variable, one can also add a value to the current value of the variable using +=, for example:
a = 100; // Assigning a simple
value
b = 200;
c = 300;
a += b; // Assigning with operation
a = b + c; // Assigning with expression
Similarly, you can subtract using -=, multiply using *=, divide using /=, or use bitwise operators using |=, &=, or ^=. You can also add or subtract one from a value using ++, --. For further information see the section on Expressions.
Note that you cannot do the following (or any variation):
var a, b, c;
a = b = c = 4;
And instead it should be done as:
a = 4;
b = 4;
c = 4;