One way to “make something happen” is to evaluate an expression that has side effects. Expressions with side effects, such as assignments and function invocations, can stand alone as statements, and when used this way they are known as expression statements. A similar category of statements are the declaration statements that declare new variables and define new functions.
- Loops are statements like while and for that execute other statements repetitively.
- Jumps are statements like break, return, and throw that cause the interpreter to jump to another part of the program.