How to run javascript code without using a browser_javascript tips

Sometimes we want to write a small program in js, but we find it troublesome to run it using a browser. So now let's take a look at how to use a java program to call a javascript program, so that the js code can be executed without the help of a browser. .

The reason for this requirement is because I encountered such a problem in a project I was working on these days. I have a javascript script, but the other codes of this project are all written in CC. I don’t want to use js Converting the code to C felt too troublesome, so I thought it would be great if I could directly call the javascript code under C, or there would be a tool in the shell that can directly run the js code without using a browser. Now you can use java code to call javascript code. You can write a shell script to encapsulate it and run the js code directly under the shell.

First of all, if you want to install java.

The java code is as follows:

Copy the code The code is as follows:

import java .io.FileReader;
import javax.script.ScriptEngine;
import javax.script.ScriptEngineManager;
public class RunScriptFile {
public static void main(String[] args) {
ScriptEngineManager manager = new ScriptEngineManager();
ScriptEngine engine = manager.getEngineByName("js");
try {
FileReader reader = new FileReader("testFile.js");
engine.eval( reader);
reader.close();
} catch (Exception e) {
e.printStackTrace();
}
}
}

For example, the js code to be run is as follows:

Copy the code The code is as follows:

function add (a, b) {
c = a b;
return c;
}
result = add (10, 5);
print ('Result = ' result);

Then run in the shell:
javac RunScriptFile.java
java RunScriptFile
The generated result is as follows:
Result = 15