The IF Statement 1 conditional statement is used to test the condition.

1. Grammar:

if (condition)

{

JavaScript code;

}

If you want to execute multiple statements, you must place these statements within a pair of curly braces ({}). But if you just execute one statement, you can omit the curly braces

2. Conditional statement Writing specification; In order to improve the readability of the code, we usually do not write if statements in one line, but rather into a more clear form of writing;

if (condition)

{

JavaScript code;

}

If condition to judge statement if (condition) {command 1}else{command 2} Execute command 1 if the condition is satisfied, and execute command 2 if it is not satisfied;