I am new to Perl and trying to decode a Perl script which reads an Excel file and export the data into a text file. One of the steps in the script is performing weirdly.
This is the step:
@array_name = grep {$_} @array_name;
This step just truncates the last column if the value is 0; otherwise it works properly. If I remove this step, the last column with value 0 is back, but it includes some dummy NULL columns in my extract which are not part of my source Excel file.
Can someone please help me understand this step?
The grep command filters non empty content. So everything that does not evaluate as true will be discarded. Empty cells and cells containing 0 will be removed. If you just want to remove empty cells you could use
@array_name = grep { defined && length } @array_name ;
instead.
Answer：
$A->[$i][10]=~s/\n//g;
$variable_value =~s/\n//g;
$variable_value is the variable in which the value is stored.
It will remove the next line.
Answer：
grep basically returns all true values from the array, and 0 is interpolated as false.
For example grep is used here to filter true values into @b,
my @dirty = (0,1,2,3,,0,5,);
my @clean = grep {$_} @dirty;
for(@clean) {print "$_\n";}
Returns
1
2
3
5
A little trick for preserving the zeros involves adding a newline to the grep argument:
my @dirty = (0,1,2,3,,0,5,);
my @clean = grep {"$_\n"} @dirty;
for(@clean) {print "$_\n";}
Which returns,
0
1
2
3
0
5
