C#•16mo ago

❔ LINQ

Does linq have its own replace method? If so, does it make a new string or modify? Also is there a way to replace a string without making new string?

21 Replies

Angius•16mo ago

Wym a replace method? And no, strings are immutable So unless you get into the unsafe territory and start swapping bytes around... no, you can't change a string without making a new string

mattuOP•16mo ago

.replace()

Angius•16mo ago

Yeah, and why would LINQ need this method? What would you want to replace with it? Because string already does have a replace method

mtreit•16mo ago

What's your starting point? A list of strings?

mattuOP•16mo ago

yeah like words i mean it's okay I think i know a way to work around something anyway

Angius•16mo ago

And you want to replace every "dog" into "cat" or some such? ["dog", "is", "dog"] into ["cat", "is", "cat"] for example?

mattuOP•16mo ago

yeah but i have it an a loop to find different words and it creates a new string everytime. so it would just return the latest string. The thing is I would want it to add on top of each other and it replaces the string with user input

mtreit•16mo ago

In LINQ you can use Select to project an original sequence into a new sequence.

MODiX•16mo ago

mtreit

REPL Result: Success

            var strings = new List<string>() { "A", "B", "C" };
            var updated = strings.Select(x =>
            {
                if (x == "A")
                {
                    return "Z";
                }

                return x;
            });

            foreach (var s in updated)
            {
                Console.WriteLine(s);
            }

            var strings = new List<string>() { "A", "B", "C" };
            var updated = strings.Select(x =>
            {
                if (x == "A")
                {
                    return "Z";
                }

                return x;
            });

            foreach (var s in updated)
            {
                Console.WriteLine(s);
            }

Console Output

Z
B
C

Z
B
C

Compile: 787.350ms | Execution: 91.401ms | React with ❌ to remove this embed.

mtreit•16mo ago

If I was starting with a List I probably wouldn't use LINQ but if you want to, that's one way to approach it.

mattuOP•16mo ago

oh alr what if you wanted to change a and c

mtreit•16mo ago

Add more logic inside the lambda

Angius•16mo ago

You could define a dictionary of replacements too

MODiX•16mo ago

mtreit

REPL Result: Success

var strings = new List<string>() { "A", "B", "C" };
var updated = strings.Select(x =>
{
    return x switch
    {
        "A" => "Z",
        "C" => "Y",
        _ => x
    };
});

foreach (var s in updated)
{
    Console.WriteLine(s);
}

var strings = new List<string>() { "A", "B", "C" };
var updated = strings.Select(x =>
{
    return x switch
    {
        "A" => "Z",
        "C" => "Y",
        _ => x
    };
});

foreach (var s in updated)
{
    Console.WriteLine(s);
}

Console Output

Z
B
Y

Z
B
Y

Compile: 759.774ms | Execution: 154.762ms | React with ❌ to remove this embed.

Angius•16mo ago

Or a switch expression, even better, yea

mattuOP•16mo ago

yeah that's good thanks guys

Florian Voß•16mo ago

why wouldn't you use Linq when its a list?

mtreit•16mo ago

Performance

Florian Voß•16mo ago

could you ellaborate a little more?

mtreit•16mo ago

LINQ in general is not great for performance so my first inclination is to avoid it if there is a trivial way to achieve the same thing. In most cases it probably doesn't matter much, but I am used to working on projects where performance is very important and the amount of data is large so LINQ is something I tend to avoid.

Accord•16mo ago

Was this issue resolved? If so, run /close - otherwise I will mark this as stale and this post will be archived until there is new activity.

Gaming

Programming

❔ LINQ