Let's say I want to skip characters and build a new string.

The string example to loop/iterate:

import std.stdio;

void main()
{
    string a="abc;def;ab";

}

The character I want to skip: ;

Expected result:

abcdefab

On Wednesday, 8 December 2021 at 11:23:45 UTC, BoQsc wrote:

import std.stdio;

void main()
{
    string a="abc;def;ab";

}

abcdefab

import std.stdio : writeln;
import std.algorithm.iteration : filter;
import std.conv : to;

void main()
{
    string a = "abc;def;ab";
    string b = a.filter!(c => c != ';').to!string;
    writeln(b);
}

On Wednesday, 8 December 2021 at 11:35:39 UTC, Biotronic wrote:

import std.stdio;

void main()
{
    string a="abc;def;ab";

}

abcdefab

I somehow have universal cross language hate for this kind of algorithm.
I'm not getting used to the syntax and that leads to poor readability.
But that might be just me.

Anyways,
Here is what I've come up with.

import std.stdio;

void main()
{
    string a = "abc;def;ab";
	string b;
	
	for(int i=0; i<a.length; i++){
		write(i);
		writeln(a[i]);
		if (a[i] != ';'){
			b ~= a[i];
		}
		
	}
	
    writeln(b);
}

On Wednesday, 8 December 2021 at 12:49:39 UTC, Adam D Ruppe wrote:

Thanks Adam.

This is how it would look implemented.

import std.stdio;

void main()
{
    string a = "abc;def;ab";
	string b;
	
	foreach(ch; a) {
		if (ch != ';'){
			b ~= ch;
		}
	
		writeln(ch);
	}
	
    writeln(b);
}

On Wednesday, 8 December 2021 at 11:23:45 UTC, BoQsc wrote:

import std.stdio;

void main()
{
    string a="abc;def;ab";

}

abcdefab

string b = a.replace(";", "");

On Wednesday, 8 December 2021 at 14:16:16 UTC, bauss wrote:

import std.stdio;

void main()
{
    string a="abc;def;ab";

}

abcdefab

Thanks, that's what I used to do few years ago.
It's a great solution I forget about and it works.

import std.stdio;
import std.array;

void main()
{
    string a="abc;def;ab";
	string b = a.replace(";", "");
	writeln(b);
}

On Wednesday, 8 December 2021 at 14:27:22 UTC, BoQsc wrote:

import std.stdio;

void main()
{
    string a="abc;def;ab";

}

abcdefab

import std.stdio;
import std.array;

void main()
{
    string a="abc;def;ab";
	string b = a.replace(";", "");
	writeln(b);
}

It's also worth noting the differences in compiler output, as well as the time taken to compile, these two approaches:

(1)
string str = "abc;def;ab".filter!(c => c != ';').to!string;

(2)
string str = "abc;def;ab".replace(";", "");

see: https://d.godbolt.org/z/3dWYsEGsr

On Wednesday, 8 December 2021 at 22:18:23 UTC, forkit wrote:

You're passing a literal. Try passing a runtime value (e.g. a command line argument). Also, -O2 -release :) Uless, of course, your goal is to look at debug code.

On Wednesday, 8 December 2021 at 22:35:35 UTC, Stanislav Blinov wrote:

but this will change nothing.

the compilation cost of using .replace, will always be apparent (compared to the presented alternative), both in less time taken to compile, and smaller size of executable.