What is the function of javascript flow control statement

The functions of JavaScript flow control statements: 1. Sequential structure, used to execute statements in the order they appear; 2. Conditional structure, used to determine the order of execution according to given logic; 3. Loop structure , used to determine whether to repeatedly execute a certain program based on code logic conditions.

The operating environment of this tutorial: Windows 10 system, JavaScript version 1.8.5, Dell G3 computer.

The role of javascript flow control statements

.The three basic process structures of JavaScript

(1) Sequential structure: according to the order in which statements appear Execute in sequence.

(2) Conditional structure: Determine the execution order according to the given logic. It can be divided into single, double and multiple choices. The more corresponding conditions, the more code options are available.

(3) Loop structure: Determine whether to repeatedly execute a certain program based on the code logic conditions. If the return value of the logical condition is true, the loop will be entered, otherwise the loop statement will not be executed.

JavaScript conditional control statement

·if statement is a relatively simple selection structure. If the given logical conditional expression is true, a given set of The statement

·if...else statement determines the logical condition given after if. When the condition is true, the statement in if is executed. When the condition is not true, the code in else is executed.

·if…else if nested statement selects one group among multiple groups of statements to execute

·switch The statement has the same effect as if...else if...nested statement, but it is more convenient, concise and more readable than if...else if...nested statement

3.JavaScript Loop control statement

·For loop statement, under the conditions of the loop statement, executes the statements in the loop body cyclically a specified number of times

·while The loop statement repeatedly executes the statements in the loop body if it meets the conditions of the loop statement

·do... The while loop statement has the same principle as the while loop statement, but it is an execution statement , execute the code first, and then judge the conditions, that is, the loop is executed at least once

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