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JavaScript If condition not working

zak100

Coder
Hi,
I am trying to check the if -condition, but it does not work if the condition is false. Following is my code:
Hi,

I am using isNaN(arg) in a if condition but if the arg is a null value, control enters into if condition. How can I avoid it:

My code is:
const path = require("path");
const fs = require("fs");
module.exports = async function(callback)
{
try {
let keywordStr = '11 = cccc = (bbbb sssss )= ttttttttt("")';
let words = keywordStr.split(' '); //number of lines in file

for (let i = 0; i <words.length; i++) {
word= words
console.log("word =" + word)
//NaN = not a number
if (isNaN(word) === false && word !== null){
console.log("new numeric string = " + word);
}
}
}
catch (error) {
console.log(error)
}
callback();
}

I just want to print "new numeric string = 11" butI am getting null values also:
truffle exec findnumeric.js
Using network 'development'.

word =11
testing2 new numeric string = 11
word ==
word =
testing2 new numeric string =
word =cccc
word ==
word =
testing2 new numeric string =
word =
testing2 new numeric string =
word =
testing2 new numeric string =
word =
testing2 new numeric string =
word =
testing2 new numeric string =
word =
testing2 new numeric string =
word =
testing2 new numeric string =
word =(bbbb
word =sssss
word =)=
word =ttttttttt("")
@lc2530hz:~/Truffle_programs/txorigin_assertion_script_tool$
Somebody please guide me.
Zulfi.
 
Actually your program code works fine for me, if only I change word= words to word= words[i].
Then as expected, in only prints new numeric string = 11.
Actually looking at your output, I presume you have also made that change (after posting the code here).
I'm confused by your issue with null values. You are splitting a string into parts - how can any of the parts ever be null ?
Note, I tested with Node.js, not with Turtle.
 
Last edited by a moderator:
Hi @cbreemer

I have removed the null condition, but I am still getting the same output. Maybe it was a typo that you saw :

Code:
word=words

My code is below:

JavaScript:
const path = require("path");
const fs = require("fs");
module.exports = async function(callback)
{
   try {
      let keywordStr = '11 =  cccc =        (bbbb sssss )= ttttttttt("")';
      let words =   keywordStr.split(' '); //number of lines in file
      
      for (let i = 0; i <words.length; i++) {
         word= words[i]
         console.log("word =" + word)
         //NaN = not a number
         if (isNaN(word) === false ){//if(isNaN(word)==false  && word !== null){
            console.log("testing2 new numeric string = " + word);
         }
      }
    }
    catch (error) {
          console.log(error)
    }
    callback();
}


My output is:
Using network 'development'.

word =11
testing2 new numeric string = 11
word ==
word =
testing2 new numeric string =
word =cccc
word ==
word =
testing2 new numeric string =
word =
testing2 new numeric string =
word =
testing2 new numeric string =
word =
testing2 new numeric string =
word =
testing2 new numeric string =
word =
testing2 new numeric string =
word =
testing2 new numeric string =
word =(bbbb
word =sssss
word =)=
word =ttttttttt("")
@lc2530hz:~/Truffle_programs/txorigin_assertion_script_tool$

Somebody please guide me.

Zulfi.
 
Ah, I see what is happening now. Contrary to what I thought, the split function works character-by-character, and does not skip over multiple occurrences of the delimiter. You get empty strings between adjacent spaces. I don't know ifs there is another split-like function that ignores extra white space, but I could not find one. So we have to filter them out. Now your null test makes some sense to me. But be aware that null and empty are different things ! As I said, no words can be null here, but they can be empty. If you add the correct test, it will work. Like this:
JavaScript:
      keywordStr = '11 =  cccc =        (bbbb sssss )= ttttttttt("")';
      words = keywordStr.split(' ');
    
      for (word of words)
      {
         if ( !isNaN(word) && word != '' )
            console.log(word + " is numeric");
         else
            console.log(word);
      }

Note that I have dispensed with the loop counter, and loop directly though the array using the for..of statement.
Also I have changed isNaN(word) === false to !isNaN(word). Never make things more complicated than they have to be.
 
Last edited by a moderator:

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