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I want to split the string below by a default comma which is , and ignore the "," part.
Has anyone come up with a solution for this? Tried a bunch of solutions, but doesn't work.
My string: (testing","a framework), hello world, testing","antother_framework
expected result:
["testing","a framework", "hello world", "testing","antother_framework]
not the nicest way, with regex you could grouped the replace but it works
const str = '(testing","a framework), hello world, testing","antother_framework';
let arr = str.split(',');
console.log(arr);
for (let i = 0; i < arr.length; i++) {
arr[i] = arr[i].replaceAll('(', '');
arr[i] = arr[i].replaceAll(')', '');
arr[i] = arr[i].replaceAll('\"', '');
arr[i] = arr[i].trim();
}
console.log(arr);
You could use this function:
function splitByCommas(str) {
return str.split(/,(?=(?:[^"]*"[^"]*")*[^"]*$)/);
}
Explanation:
/,(?=(?:[^"]"[^"]")[^"]$)/ -> match the comma outside of the quotes
(?:[^"]"[^"]")* -> match the quotes and the text inside the quotes
[^"]*$ -> match the remaining text after the last quote
If you run the function like this:
console.log(splitByCommas('(testing","a framework), hello world, testing","antother_framework'));
It will give the following output:
[
'(testing","a framework)',
' hello world',
' testing","antother_framework'
]
If you want to also trim the whitespaces, you can use this:
function splitByCommas(str) {
return str.split(/,(?=(?:[^"]*"[^"]*")*[^"]*$)/).map(function (item) {
return item.trim();
}
);
}
For the same input giving you:
[
'(testing","a framework)',
'hello world',
'testing","antother_framework'
]
Related
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how to get first 2 character of string in javascript like this "Hello world " => get this "wo"?
another example
"Osama Mohamed" => M.
you can use string.split(' '), this function will split you string into an array, for example:
let s = "Hello World";
console.log(s.split(" ")) // will log ["Hello", "World"]
then you can get the second word using array[index] when index the index of your desired word in said array.
now using string charAt we can get the first letter of the word.
now to put everything together:
let s = "Hello World"
let s_splited = s.split(" ") // ["Hello", "World"]
let second_word = s_splited[1]
console.log(second_word.charAt(0))
string = "Hello world";
split_string = string.split(" ");
second_word = split_string[1]
first_char = second_word[0]
console.log(first_char)
OR
string = "Hello world";
console.log(string.split(" ")[1][0])
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I have a situation to manipulate a given string which is separated by comma and reverse the given string.
Input: hello,world,wow
Expected Output: wow,world,hello
First split the string by the comma. Then reverse the array. Then turn it back into a string.
let foo = 'hello,world,wow' // assign the string
foo = foo.split(',') // splits by comma
foo = foo.reverse() // reverses the array
foo = foo.join() // converts array back into a comma separated string
var initialString = "hello,world,wow"
var finalString = initialString.split(",").reverse().join(",");
console.log(finalString) // "wow,world,hello"
Here is the solution to reverse the given string.
let str = "hello,world,wow";
let temp = str.split(",");
let output = "";
// Index will starting from last element
let index = (temp.length - 1);
for(let k=0; k<temp.length; k++){
if(k == (temp.length - 1)){
// Last Element so no need of comma
output += temp[index];
}
else {
// Adding commas to the output
output += temp[index]+",";
}
index--;
}
alert(output);
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Following are 2 strings:
" at callback (/Users/lem/Projects/RingAPI/packages/server/node_modules/loopback-connector-rest/lib/rest-builder.js:541:21)"
" at /Users/lem/Projects/RingAPI/packages/server/node_modules/#loopback/repository/node_modules/loopback-datasource-juggler/lib/observer.js:269:22"
How do I split them to these using JS and Regex?
['callback', '/Users/lem/Projects/RingAPI/packages/server/node_modules/loopback-connector-rest/lib/rest-builder.js', '541', '21']
['', '/Users/lem/Projects/RingAPI/packages/server/node_modules/#loopback/repository/node_modules/loopback-datasource-juggler/lib/observer.js', '269', '22']
try regexp named groups
https://github.com/tc39/proposal-regexp-named-groups
it adds result readability for such strange regexes ;)
const strings = [
" at callback (/Users/lem/Projects/RingAPI/packages/server/node_modules/loopback-connector-rest/lib/rest-builder.js:541:21)",
" at /Users/lem/Projects/RingAPI/packages/server/node_modules/#loopback/repository/node_modules/loopback-datasource-juggler/lib/observer.js:269:22"
];
const regex = /^\s*?at\s?(?<source>.*?)\s\(?(?<path>.*?):(?<row>\d*):(?<column>\d*)/;
strings.forEach(string => {
const result = string.match(regex);
resultElement.innerHTML +=
'\n' + JSON.stringify({string, "result.groups": result.groups}, null, 4)
})
<pre id="resultElement"/>
You can use regex for such purpose, i.e:
const regex = /at( (?:[a-z]+)?)\(?(.+)\:(\d+)\:(\d+)\)?/;
//const str = " at callback (/Users/lem/Projects/RingAPI/packages/server/node_modules/loopback-connector-rest/lib/rest-builder.js:541:21)";
const str = " at /Users/lem/Projects/RingAPI/packages/server/node_modules/#loopback/repository/node_modules/loopback-datasource-juggler/lib/observer.js:269:22";
const found = str.match(regex);
found.splice(0, 1)
console.log(found)
It works for both strings!
I've wrote simple parse function for you:
function parse(string) {
const functionName = string.match(/at .* /);
return [
...(functionName && [functionName[0].slice(2).trim()] || ['']),
...string.match(/\/.*/)[0].split(':')
];
}
First of all I try to extract function name. If it exists I remove 'at' word and use trim function to remove unnecessary spaces. Then I look for substring beginning with slash '/' and match every character after it. Last step is to split returned string.
I believe it matches your requirements.
I've also prepared demo in stackblitz: https://stackblitz.com/edit/js-ol22yf
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Using Javascript is there a way to remove extra occurrences of a specific letter in a string?
For example:
remove_extra('a', 'caaaat')
//=> 'cat'
I know there must be a brute force way to do something like this but is there an elegant way? I'm not sure how to approach this algorithm.
you can do this with regex:
var test = "aaabbbccc";
console.log(test.replace(/(.)(?=.*\1)/g, "")); //would print abc
var test2 = "caaaaat";
console.log(test2.replace(/(.)(?=.*\1)/g, "")); //would print cat
Sorry, I misunderstood your question.
To only keep one instance of specified char:
function onlyOneCharOf(string, pattern) {
let first = true;
//if (pattern.length !==1) throw Error("Expected one character");
pattern=pattern.replace(/[.*+?^${}()|[\]\\]/g, '\\$&'); //escape RegEx special chars
return string.replace(new RegExp(pattern, "g"), value => {
if (first) {
first = false;
return value;
}
return "";
});
}
console.log(onlyOneCharOf("zzzzzaaabbbbcccc", "a"));
Note: the pattern given to the function is used to create a RegEx. Since some characters are special characters, those characters must be escaped. I updated the function to do that for you. You might also want to check the length, but the length might be larger than 1 for some unicode code points.
If you only want any character to appear once, you can use a Set:
function unique(string) {
return Array.from(new Set(string.split(''))).join('');
}
console.log(unique("caaaat"));
A value in a Set may only occur once.
You can use Array.from to explode a string:
Array.from('caaaat');
//=> ["c", "a", "a", "a", "a", "t"]
You can then use Array#filter to keep everything that is neither "a" nor the first occurrence of "a":
Array.from('caaaat').filter((x, i, xs) => x !== 'a' || xs.indexOf(x) === i).join('');
//=> "cat"
(I leave it to you as an exercise to put this into a reusable function.)
Just be aware that if you choose to interpret char as a regular expression without validating it first, you may have unexpected results:
function onlyOneCharOf(string, char) {
let first = true;
return string.replace(new RegExp(char, "g"), value => {
if (first) {
first = false;
return value;
}
return "";
});
}
onlyOneCharOf('caaat', '.');
//=> "c"
onlyOneCharOf('caaat', '?');
//=> SyntaxError
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I have a requirement to remove last n characters from string or remove 'page' from a particular string.
Eg:
var string = 'facebookpage';
Expected output string = 'facebook'
I would like to remove 'page' from the string.
Done it using substring.
var str = "facebookpage";
str = str.substring(0, str.length - 4);
Could you help me to find some better way to do it.
Regex for this:
//str - string;
//n - count of symbols, for return
function(str, n){
var re = new RegExp(".{" + n + "}","i");
return str.match(re);
};
EDIT:
For remove last n characters:
var re = new RegExp(".{" + n + "}$","i");
return str.replace(re, "");
UPDATE:
But use regex for this task, not good way; For example, AVG Runtime for 100000 iterations:
Str length solution = 63.34 ms
Regex solution = 172.2 ms
Use javascript replace function
var str = "facebookpage";
str = str.replace('page','');
You can use this regular expression :
(.*)\\w{4}
code :
var regex =(new RegExp("(.*)\\w{4}"))
val output = regex .exec("facebookpage")
// output is : ["facebookpage", "facebook"]
// output[1] is the Expected output which you want.
Hope this helps.