CODEWITHSUNDEEP
javascriptstringloops
apples-oranges
apples-oranges

Reputation: 987

JS get max first n values from a string

I need to capture maximum 5 elements of a string. However if there are less than 5, then I just need how many there are there.

var y = '1,2,3,4,5,6,7,8,9,10'        
//desired result: 
var out = '1,2,3,4,5' // please note there is no trailing comma



var y = '1,2,3'
//desired result: 
var out = '1,2,3'

My code:

  for (var i = 0; i < 5; i++) {
    x += y;
     x = x + ",";
   }


Write(x);

Upvotes: 0

Views: 57

Answers (3)

savageGoat
savageGoat

Reputation: 1546

var string = '1, 2, 3, 4, 5, 6, 7, 8, 9, 10';
var out = (string.match(/^([0-9],? ?){0,5}/)[0] || '').replace(/, ?$/, '');
console.log(out)

[EDIT] Explanation .match(^([0-9],? ?){0,5}/g):

  • start at the begging ^
  • match numbers [0-9]
  • then a comma if any and a space if any ,? ?.
  • match this expression 0 to 5 times {0, 5}

Upvotes: 1

Sparrow
Sparrow

Reputation: 390

Try this simple function to do that

function getMaxLen(str) {
  if(typeof str != 'string') return null;
  str = str.split(',');
  return str.slice(0, 5).join(',');
}

console.log(getMaxLen('1,2,3,4,5,6,7,8,9,10'))
console.log(getMaxLen('1,2,3'))

Upvotes: 1

Jamiec
Jamiec

Reputation: 136154

A simple method will do. The below splits the string by , then takes either n elements or the total length if it is less than n and then rejoins the values with a comma

const getNValues = (str, n) => {
   const values = str.split(",");
   const res = values.slice(0, Math.min(values.length,n))
   return res.join(",");
}


console.log(getNValues("1,2,3,4,5,6,7,8,9",5));
console.log(getNValues("1,2,3",5));

Upvotes: 2

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