I have this code:

var returnValue = item.fname + " " + item.mname + " " + item.lname
returnValue.replace(null," ");
return returnValue ;

Sometimes one of the fields is null so returnValue is:

"John null Doe"

or

"John something null"

I want to get rid of the "null" but my code does not seem to work.

Can someone help me out here?

I have this code:

var returnValue = item.fname + " " + item.mname + " " + item.lname
returnValue.replace(null," ");
return returnValue ;

Sometimes one of the fields is null so returnValue is:

"John null Doe"

or

"John something null"

I want to get rid of the "null" but my code does not seem to work.

Can someone help me out here?

• javascript
• string

• 4 returnValue.replace('null'," ");? Replace the null object, with null as a string – BritishWerewolf Commented Oct 19, 2018 at 12:40
• 3 Instead of removing null afterwards, add a check to your fields and only add them if they are not null to avoid the issue alltogether. Otherwise, what would happen if someones name is 'Joe Nullmann'? – Rence Commented Oct 19, 2018 at 12:40
• @Sirence He'll bee 'Joe mann' and may finally get a value out of his name – D.Schaller Commented Oct 19, 2018 at 14:00

7 Answers 7

Rather than replacing null afterwards, only append the individual names if they are not null.

var returnValue = "";

if (item.fname !== null) {
    returnValue += item.fname + " ";
}

if (item.mname !== null) {
    returnValue += item.mname + " ";
}

if (item.lname !== null) {
    returnValue += item.lname;
}

return returnValue;

Alternatively, use Array.prototype.filter to remove nulls:

// store the names in an array
var names = [ item.fname, item.mname, item.lname ];

// filter the array to values where they are `!== null`
var notNullNames = names.filter(x => x !== null);

// join them with spaces
var returnValue = notNullNames.join(" ");

var returnValue = (item.fname || " ") + " " + (item.mname || " ") + " " + (item.lname || " ");
return returnValue;

Be careful with mixing var types (string and null for example). Better make sure the variable is set or has a fallback.

I'd remend you another technique: place your string parts to array, filter it and join it:

[item.fname, item.mname, item.lname].filter(v => !!v).join(' ')

try this

>    return (item.fname ? item.fname : '')  + " " + (item.mname ? item.mname : '') + " " + (item.lname ? item.lname : '');

var returnValue = item.fname

if(item.mname)returnValue  += " " + item.mname

 if(item.lname)returnValue  += " " + item.lname

return returnValue 

Try ternary operator for null avoiding:

var returnValue = item.fname + " " + item.mname ? item.mname : "" + " " + item.lname

In my opinion, the most elegant solution is:

[item.fname, item.lname, item.lname].join(' ');

For example:

const item = {}
item.fname = 'foo'
item.lname = 'bar'

console.log([item.fname, item.mname, item.lname].join(' '))

Otherwise you can use the or operator to skip falsy objects:

const item = {}
item.fname = 'foo'
item.lname = 'bar'

const joined = (item.fname || '') + " " + (item.mname || '') + " " + (item.lname || '')

console.log(joined)