如何修剪在 Javascript 中具有多行的字符串

Question

I have a string with multiple lines which has a single line break between each lines. For that I first trim the extra line breaks and then split the string. The code used is -

function trimString(a){
    var i = a.length;
    var x;
    for (var j = 0; j < i; j++) {
        x = a[j].replace(/^\s*\n/gm,"");
        a[j] = x;
    }
}

function splitLogs(a,s1,s2,s3,s4,s5){
    var i = a.length;
    var x =[];
    for (var j = 0; j < i; j++) {
        x = a[j].split("\n");
        s1.push(x[0]);
        s2.push(x[1]);
        s3.push(x[2]);
        s4.push(x[3]);
        s5.push(x[4]);
        
    }
}

And the above code works fine .

But the issue is when I have a null/blank value in the multi-line string. Whenever a null value is present in a line the string is separated by two line breaks

String1 sample:

line1:Processor
    
line2:  
line3:xyz
    
line4:10
    
line5:user
    
line6:zzz

 

String2 sample:

line1:xy
    
line2:xz
    
line3:qw
    
line4:10
    
line5:df

line6:gg

For the above case If I use the trimString() function the new string obtained is -

line1:Processor
line3:xyz
line4:10 
line5:user
line6:zzz

which does not serve my purpose of retaining the null value for line2 and results in mixing up line3 values to line2 array values.

Is there any way in which I can split the string and push it to respective variables which I have to dump to a database.

Answer 1

1 - split into separated lines

2 - trim strings

3 - remove empty lines

4 - join it with \\n separator.

const resultString = targetString
  .split('\n')
  .map(line => line.trim())
  .filter(line => Boolean(line))
  .join('\n')

Your function would look like this:

function trimString(a){
  return a.split('\n')
          .map(line => line.trim())
          .filter(line => Boolean(line))
          .join('\n')
}