JavaScript Basics (If, if else, else if, while, switch...case statements)

- , Statement

Concept: a semicolon (;) represents the end of a statement

Habit: Write only one statement on a single line; write multiple statements on a line (poor code readability)

Statement BLOCK: You can include multiple statements "{}" to wrap multiple statements

U conditional statements

* If statement

* If...else Statement

* ELSE if statement

* Switch...case Statement

If statement:

If...else statement:

Switch...case statement:

The U-loop statement-----[SWITCH: Case statements are rewritten as if statements]

Concept: Controls whether [repeat] a segment specifies a block of content by a single condition

* While statement * Do...while statement

while (expression) {do {

Statement BLOCK statement block

}} while (expression)

While statement:

* The Do...while statement differs from the while statement:

* For statement

Initialize expression-Define variable content for loop control

Conditional judgment expression-used to determine whether a specified block of statements is executed repeatedly

loop control expression-the value of the variable used to manipulate the loop control

* The difference between a while statement and a for statement

• ? Jump statement

Applies to do, do, and for loops

* Break statement: Represents an interrupt, used in a circular statement-indicates that the end loop can be used for a switch statement

* Continue statement: continuous; Use in loop statement-means end "This" loop

JavaScript Basics (If, if else, else if, while, switch...case statements)