node . js process . hasuncutexceptioncapturecallback()方法

原文:https://www . geeksforgeeks . org/node-js-process-hasuncassetexceptioncapturecallback-method/

process . hasuncassetexceptioncapturecallback()方法是流程模块的内置应用编程接口,用于获取是否使用 process . setuncassetexceptioncapturecallback()方法设置了回调。

语法:

process.hasUncaughtExceptionCaptureCallback()

参数:此方法不接受任何参数。 返回值:返回一个布尔值,该值指定是否使用 process . setuncassetexceptioncapturecallback()设置了回调。

以下示例说明了在 Node.js 中使用process . hasuncassetexceptioncapturecallback()方法:

例 1:

java 描述语言

// Node.js program to demonstrate the   
// process.hasUncaughtExceptionCaptureCallback() Method

// Include process module
const process = require('process');

console.log(process.hasUncaughtExceptionCaptureCallback());

// Printing whether a callback is set or not
if(process.hasUncaughtExceptionCaptureCallback()) {
    console.log("A callback has been set using "
    + "process.setUncaughtExceptionCaptureCallback() method");
}else{
        console.log("No callback has been set using "
        + "process.setUncaughtExceptionCaptureCallback() method");
}

输出:

false
No callback has been set using process.setUncaughtExceptionCaptureCallback() method

例 2:

java 描述语言

// Node.js program to demonstrate the   
// process.hasUncaughtExceptionCaptureCallback() Method

// Include process module
const process = require('process');

function to_be_called(ex){
    console.log(ex);
}

// Setting callback 
process.setUncaughtExceptionCaptureCallback(to_be_called);

console.log(process.hasUncaughtExceptionCaptureCallback());

// Printing whether a callback is set or not
if(process.hasUncaughtExceptionCaptureCallback()){
    console.log("A callback has been set using "
    + "process.setUncaughtExceptionCaptureCallback() method");
}else{
    console.log("No callback has been set using "
    + "process.setUncaughtExceptionCaptureCallback() method");
}

输出:

true
A callback has been set using process.setUncaughtExceptionCaptureCallback() method

注意:以上程序将使用 node filename.js 命令编译运行。 参考:https://nodejs . org/API/process . html # process _ process _ hasunchargetexceptioncapturecallback