What is the difference between settimeout and setinterval

The difference between settimeout and setInterval: 1. Trigger time, settimeout is one-time, it executes the function once after setting the delay time, while setinterval is repetitive, it will repeat at a set time interval Execution function; 2. Number of executions, settimeout is only executed once, while setinterval will be executed repeatedly until canceled.

# Operating system for this tutorial: Windows 10 system, Dell G3 computer.

settimeout and setinterval are two timer functions commonly used in JavaScript, and they are very useful when writing programs. The difference between them is the trigger time and the number of executions.

First of all, the settimeout function is a one-time timer, which will execute the specified function once after the set delay time. It accepts two parameters: callback function and delay time in milliseconds. For example, the following code will execute the specified function after a delay of 2 seconds:

setTimeout(function() {
  console.log("Hello, World!");
}, 2000);

In this example, "Hello, World!" will be printed on the console after a delay of 2 seconds.

In contrast, the setinterval function is a repetitive timer that repeatedly executes the specified function at a set time interval. It also accepts two parameters: callback function and time interval in milliseconds. For example, the following code will execute the specified function once every second:

setInterval(function() {
console.log("Hello, World!");
}, 1000);

In this example, "Hello, World!" will be printed on the console every second.

Therefore, the difference between settimeout and setinterval can be summarized as follows:

1. Trigger time: settimeout is one-time, it executes the function once after setting the delay time, while setinterval is repeated Sexually, it will execute the function repeatedly at set intervals.

2. Number of executions: settimeout is only executed once, while setinterval will be executed repeatedly until canceled.

It should be noted that the execution time of settimeout and setinterval is not absolutely accurate. They are affected by the JavaScript running environment and may have some minor delays.

In actual programming, we can choose the appropriate timer function according to our needs. If we only need to execute a function once after a certain delay, then settimeout is a better choice. If we need to execute a function repeatedly at fixed intervals, then setinterval is more appropriate. At the same time, we also need to be careful to avoid abusing timer functions to avoid negative impact on performance.

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