我不想在javascript上重复相同的代码**新**

Question

I'm quite new at this.... its to create a quote from three sections of the phrase: start. middle and end... and randomly select one from each.

The code works but I didn't want to repeat the code underneath with the Math.floor/Math.Random three times.

Any ideas on how to not repeat the code?

Thanks!

var quotes = {
  start: ["start1 ", "start2 ", "start3 "],
  middle: ["middle1 ", "middle2 ", "middle3 "],
  end: ["end1 ", "end2 ", "end3 "],
 };
 var quoteRandom = "";
 for (var y in quotes) {
 console.log(quotes[y]);
}

 quoteRandom += quotes.start[Math.floor(Math.random() * 3)]; 
 quoteRandom += " " + quotes.middle[Math.floor(Math.random() * 3)]; 
 quoteRandom += " " + quotes.end[Math.floor(Math.random() * 3)];

 console.log(quoteRandom);

Answer 1

You could take the power of a function and a callback, which is basically a function for another function which calls the function for each of item of an array, for example.

Methods used:

• Object.values for getting all values of an object

• Array#map for returning a value for each item (in this case take the array and return a random item)

• and a function for getting a random value out of an array.

 function getRandomValue(array) { return array[Math.floor(Math.random() * array.length)]; } var quotes = { start: ["start1 ", "start2 ", "start3 "], middle: ["middle1 ", "middle2 ", "middle3 "], end: ["end1 ", "end2 ", "end3 "], }, quoteRandom = Object.values(quotes).map(getRandomValue).join(' '); console.log(quoteRandom); 

Answer 2

Just wrap Math.floor(Math.random() * 3) as return value of function and reuse same function where ever required to avoid duplicate lines of code

 var quotes = { start: ["start1 ", "start2 ", "start3 "], middle: ["middle1 ", "middle2 ", "middle3 "], end: ["end1 ", "end2 ", "end3 "], }; var quoteRandom = ""; for (var y in quotes) { console.log(quotes[y]); } function test(){ return Math.floor(Math.random() * 3) } quoteRandom += quotes.start[test()]; quoteRandom += " " + quotes.middle[test()]; quoteRandom += " " + quotes.end[test()]; console.log(quoteRandom); 

code sample - https://codepen.io/nagasai/pen/zWGwPg?editors=1111

Answer 3

use array.reduce() . This way you don't have to worry about start , middle and end length

 var quotes = { start: ["start1 ", "start2 ", "start3 "], middle: ["middle1 ", "middle2 ", "middle3 "], end: ["end1 ", "end2 ", "end3 ","end4 ", "end5 ", "end6"], }; var quoteRandom = [quotes.start,quotes.middle,quotes.end].reduce((str,el)=> {return str+=el[Math.floor(Math.random() * el.length)]},""); console.log(quoteRandom);