This question already has answers here:
How to count string occurrence in string?
(40 answers)
Closed 6 years ago.
If you want to count the number of occurrences of one string inside another, which approach is better in terms of simplicity and/or performance? -
using indexOf in a for/while loop
using a regular expression
And if it is the latter, then what is the best way to do it?
Try the following regular expression:
var temp = "This is a string.";
var count = (temp.match(/is/g) || []).length;
alert(count);
Related
This question already has answers here:
Why do regex constructors need to be double escaped?
(5 answers)
Is there a RegExp.escape function in JavaScript?
(18 answers)
Closed 1 year ago.
Here's the code that declares the same pattern in two different ways
let reg = new RegExp("\d+"); // 1st way
let reg2 = /\d+/; // 2nd way
let string = "one two 100";
console.log(reg.test(string)); // false
console.log(reg2.test(string)); // true
I was reading the book "Eloquent JavaScript" and they said these two ways of declaring regex are equivalent but I don't know why the code above is producing different results.
This question already has answers here:
How can I split a string into segments of n characters?
(17 answers)
How do you use a variable in a regular expression?
(27 answers)
Closed 2 years ago.
I'm struggling with a very simple problem.
lines = "hogefoobarwai"
I want to cut this string into 4 characters.
Like this.
hoge, foob, arwa, i
How to split?
I try to use split() with regex.
let vars = lines.match(/.{4}/g);
This is good. But if something like {4} is variable, it won't work.
for example
length = 6
let vars = lines.match(/.{length}/g);
this shows literally /.{length}/.
If anyone can tell me what it is, please let me know.
You could take a minimum length of one (for getting smaller substrings) and the length and build a new regular expression.
const
lines = "hogefoobarwai",
length = 4,
parts = lines.match(new RegExp(`.{1,${length}}`, 'g'));
console.log(parts);
try using a dynamically generated Regex:
const newRegEx = new RegEx('{' + length + '}', g)
This question already has answers here:
How can I get query string values in JavaScript?
(73 answers)
Closed 5 years ago.
I'm gonna to write regex or other expression to get coordinates after '='.
My example:
var cords = https://maps.googleapis.com/maps/api/staticmap?center=50.082961,19.966860&zoom=13&size=300x300&sensor=false&markers=color:orange%7C50.082961,19.966860&client=gme-marktplaats&channel=bt_pl&signature=lPDQWiNQ2_mY8xgoVthZHLLYWac=
I want to get 50.082961,19.966860
I know that I could use slice but I think I could write it better with regex.
Simple base for this example: \=(.[0-9]) What's next?
Try this center\=(\d+\.\d+,\d+\.\d+)&
var val = 'https://maps.googleapis.com/maps/api/staticmap?center=50.082961,19.966860&zoom=13&size=300x300&sensor=false&markers=color:orange%7C50.082961,19.966860&client=gme-marktplaats&channel=bt_pl&signature=lPDQWiNQ2_mY8xgoVthZHLLYWac='.match(/center\=(\d+\.\d+,\d+\.\d+)&/)[1]
console.log(val)
But as other's have commented, you likely shouldn't be using regex for this purpose
This question already has answers here:
Regex using javascript to return just numbers
(14 answers)
Closed 6 years ago.
with the following code can get the 1 in the string.
var match = /[0-9]+/.exec('[1][2]');
console.log(match);
How do i get the 2 and not the 1 ?
Try with this regex
console.log(/(\[[0-9]\])+/.exec('[1][2]'));
I think it's only a matter of escaping the square brackets
This question already has answers here:
How do I split a string, breaking at a particular character?
(17 answers)
Closed 8 years ago.
I have a string that always contains 8 variable values that are separated with a hypen (-) like in the following example:
5-2-2-2-2-2-2-1
What is the best way to split this into 8 separate values so that I can use each of them in a variable if the values can be either an integer or the value 'n/a' ?
Many thanks for any help with this, Tim.
var str = '5-2-2-2-2-2-2-1';
var parts = str.split('-');
for (var i=0;i<parts.length;i++){
console.log(parts[i]);
}
You are searching for the String.split() method