1. What is a JavaScript timer?
In JavaScript, we can execute code after a set time interval instead of executing it immediately after the function is called.
2. Timer type
One-shot timer: Fires only once after the specified delay time.
Interval trigger timer: trigger once every certain time interval
3. Timer method
1): One-time timer
A):setTimeout(): Execute the code after the specified delay time, and execute it once
Syntax: setTimeout(code, delay time);
Parameter description:
1. The function to be called or the code string to be executed.
2. Delay time: the time to wait before executing the code, in milliseconds (1s=1000ms).
B):clearTimeout():Cancel setTimeout() setting
Syntax: clearTimeout(timer)
Parameter description:
timer: ID value returned by setTimeout(). This value identifies the deferred execution code block to be canceled.
Call setTimeout() and clearTimeout() delay methods:
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