Add content on to the beginning of something (usually a file).
Questions tagged [prepend]
475 questions
635
votes
6 answers
What's the idiomatic syntax for prepending to a short python list?
list.append() is the obvious choice for adding to the end of a list. Here's a reasonable explanation for the missing list.prepend(). Assuming my list is short and performance concerns are negligible, is
list.insert(0, x)
or
list[0:0] =…
hurrymaplelad
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292
votes
10 answers
Most efficient way to prepend a value to an array
Assuming I have an array that has a size of N (where N > 0), is there a more efficient way of prepending to the array that would not require O(N + 1) steps?
In code, essentially, what I currently am doing is
function prependArray(value, oldArray) {
…
samccone
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217
votes
9 answers
.append(), prepend(), .after() and .before()
I am pretty proficient with coding, but now and then I come across code that seems to do basically the same thing. My main question here is, why would you use .append() rather then .after() or vice verses?
I have been looking and cannot seem to…
Epik
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154
votes
11 answers
How can I implement prepend and append with regular JavaScript?
How can I implement prepend and append with regular JavaScript without using jQuery?
Ben
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144
votes
17 answers
Unix command to prepend text to a file
Is there a Unix command to prepend some string data to a text file?
Something like:
prepend "to be prepended" text.txt
One Two Three
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118
votes
6 answers
Adding code to a javascript function programmatically
I'm attempting to customize an existing JS library without modifying the original JS code. This code loads in a few external JS files which I do have access to, and what I'd like to do is change one of the functions contained in the original file…
Munzilla
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103
votes
8 answers
How to insert element as a first child?
I want to add a div as a first element using jquery on each click of a button
77
votes
10 answers
Prepend a line to an existing file in Python
I need to add a single line to the first line of a text file and it looks like the only options available to me are more lines of code than I would expect from python. Something like this:
f = open('filename','r')
temp = f.read()
f.close()
f =…
Nick
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77
votes
2 answers
D3.js prepend (similar to jQuery prepend)
I like the usage of append in D3, and I'm looking for prepend.
Does this exist in D3?
Mia
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69
votes
4 answers
Prepend std::string
What is the most efficient way to prepend std::string? Is it worth writing out an entire function to do so, or would it take only 1 - 2 lines? I'm not seeing anything related to an std::string::push_front.
zeboidlund
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59
votes
5 answers
What is the idiomatic way to prepend to a vector in Clojure?
Prepending to a list is easy:
user=> (conj '(:bar :baz) :foo)
(:foo :bar :baz)
Appending to a vector is easy:
user=> (conj [:bar :baz] :foo)
[:bar :baz :foo]
How do I (idiomatically) prepend to a vector, while getting back a vector?
This does not…
0x89
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46
votes
2 answers
What's the difference between `::` and `+:` for prepending to a list)?
List has 2 methods that are specified to prepend an element to an (immutable) list:
+: (implementing Seq.+:), and
:: (defined only in List)
+: technically has a more general type signature—
def +:[B >: A, That](elem: B)(implicit bf:…
Mechanical snail
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43
votes
6 answers
jquery - keep window from changing scroll position while prepending items to a list?
I have a page that displays messages and I want it to work just like Facebook, but without the lazy loader. Messages are displayed in chronological order, most recent last.
My message list is initially populated x number of most recent messages, and…
Redtopia
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34
votes
3 answers
How to prepend int to slice
I am fairly new to Go and thus my question might seem a bit naive.
I have a slice which I created using
var x []int;
for i := 2; i < 10; i += 2 {
x = append(x, i);
}
I want to prepend an integer to this slice, something like
x = append(2,…
coda
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27
votes
2 answers
What is the difference between 'include' and 'prepend' in Ruby?
From the Module
Module#append_features(mod) → mod => When this module is included in another, Ruby calls append_features in this module, passing it the receiving module in mod. Ruby’s default implementation is to add the constants, methods, and…
Arup Rakshit
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