Formatting text with tabs or spaces

Question

I have object like this:

{
 Name: "John"
 Location: "Unknown"
 Type: "Unknown"
 Status: "Unknown"
 Phone_number: "Unknown"
}

Need to format it like this (with tabs or spaces):

Name:           John // three tabs
Location:       Unknown // two tabs
Type:           Unknown // three tabs
Status:         Unknown // three tabs
Phone_number:   Unknown // one tab

Java and Perl has this functionality in printf, but how to do this in javascript?

Drenthe

Answer 1

Ok. Found here:

/**
 * object.padding(number, string)
 * Transform the string object to string of the actual width filling by the padding character (by default ' ')
 * Negative value of width means left padding, and positive value means right one
 *
 * @param       number  Width of string
 * @param       string  Padding chacracter (by default, ' ')
 * @return      string
 * @access      public
 */
String.prototype.padding = function(n, c)
{
        var val = this.valueOf();
        if ( Math.abs(n) <= val.length ) {
                return val;
        }
        var m = Math.max((Math.abs(n) - this.length) || 0, 0);
        var pad = Array(m + 1).join(String(c || ' ').charAt(0));
//      var pad = String(c || ' ').charAt(0).repeat(Math.abs(n) - this.length);
        return (n < 0) ? pad + val : val + pad;
//      return (n < 0) ? val + pad : pad + val;
};

This not works with tabs, but works with spaces exactly how I describe in question.

For my example code will be:

$.each(myObj, function(myKey, myVal) {

   myOut += myKey.padding(20) + " = " + myVal + "\r\n";

});

Output will be:

Name                 = John
Location             = Unknown
Type                 = Unknown
Status               = Unknown
Phone_number         = Unknown

Drenthe

This is very helpful, however it doesn't work with multiple padding in one line. – Bevon

Answer 2

The String.prototype.padEnd(targetLength, padString) method will do the job, it is documented here. The padString parameter is set to a single-space string if omitted.

Example:

console.log(`   ${'Player'.padEnd(19)} ` +
    `${'MATCH'.padEnd(8) } ` +
    `${'SCORE'.padEnd(8) } `
);
for (const player of this.players) {
    console.log(` - ${player.name.padEnd(20)} ` +
        `${player.matches.length.toString().padEnd(8) } ` +
        `${player.score.toString().padEnd(8) } `
    );
}

Result:

   Player              MATCH    SCORE   
 - Bradly               5        15      
 - Sam                  4        9       
 - Dew                  3        5     

Archfiend

Cleaner example jsbin.com – Drenthe

Working with myString.padEnd(x) in combination with a monospace font is imho the best solution and should be the accepted answer. – Prejudicial

Answer 3

EDIT You can add more tabs by using '\t'. Each '\t' means one tab, so in the console.log you can use more console.log(prop + ":\t\t\t" + obj[prop]);

Pass your object to this function (this works for any object):

function printObject(obj)
  for(var prop in obj){
   if (obj.hasOwnProperty(prop)) {
    console.log(prop + ":\t" + obj[prop]);
   }
 }

You can also get a pretty similar output (but with quotes) by using

JSON.stringify(obj, null, 2); 

This will basically print your objects in jason format and will use the last argument (the 2) as the number of separator spaces.

Decoder

First function adds only one tab, if key will have long word or few words one tab will be not enough. Even in my sample first line requires two tabs. – Drenthe

@ancap Did you try to add more tabs, like :\t\t, or even :\t\t\t? – Callender

I edited first post. As you can see in first line - three tabs, in second - two, in third and fourth - three, in fifth - one. – Drenthe