I have an array of strings. i am using regular i am trying to find index of occurrence of element and remove substring from string but i have problem when i add another occurrence of character
My solution:
const names = [
'COMMENT — CODE | COUNTRY | DATE | TARGET',
'CODE| COUNTRY | DATE |TARGET',
'CODE|| COUNTRY| DATE |TARGET',
'COMMENT 1 — COMMENT 2 — CODE | COUNTRY | DATE | TARGET',
];
const exp = new RegExp(/—|-/);
const filteredNames = names.map(name => {
const index = name.match(exp)?.index;
return name.slice(index + 1)
});
My result:
"CODE | COUNTRY | DATE | TARGET"
"CODE| COUNTRY | DATE |TARGET"
"CODE|| COUNTRY| DATE |TARGET"
"COMMENT 2 — CODE | COUNTRY | DATE | TARGET" <- not correct
But expected result:
"CODE | COUNTRY | DATE | TARGET"
"CODE| COUNTRY | DATE |TARGET"
"CODE|| COUNTRY| DATE |TARGET"
"CODE | COUNTRY | DATE | TARGET"
I shall be most grateful for any help in this matter.
We could try a regex replacement approach here:
var names = [
'COMMENT — CODE | COUNTRY | DATE | TARGET',
'CODE| COUNTRY | DATE |TARGET',
'CODE|| COUNTRY| DATE |TARGET',
'COMMENT 1 — COMMENT 2 — CODE | COUNTRY | DATE | TARGET',
];
var output = names.map(x => x.replace(/(?:.*? — )*([^ |]+)/g, "$1"));
console.log(output);Here is an explanation of the regex pattern being used here:
(?:.*? — )* match (but do not capture) a "TERM — ", zero or more times
([^ |]+) then capture the final term in $1
Then, we replace each pipe delimited entry with $1, the final term.
You can just select part which you need:
const names = [
'COMMENT — CODE | COUNTRY | DATE | TARGET',
'CODE| COUNTRY | DATE |TARGET',
'CODE|| COUNTRY| DATE |TARGET',
'COMMENT 1 — COMMENT 2 — CODE | COUNTRY | DATE | TARGET',
];
const exp = new RegExp(/(\w+(\s*\|*\s*))*\w+\s*$/g);
const filteredNames = names.map(name => {
const matches = name.match(exp);
return matches?.[0] || '';
});
console.log(filteredNames);To get the last element, you can split on either type of hyphen and get the last part:
const names = [
'COMMENT — CODE | COUNTRY | DATE | TARGET',
'CODE| COUNTRY | DATE |TARGET',
'CODE|| COUNTRY| DATE |TARGET',
'COMMENT 1 — COMMENT 2 — CODE | COUNTRY | DATE | TARGET',
];
const regex = /[—-]/;
names.forEach(s => {
const parts = s.split(regex);
console.log(parts[parts.length - 1].trim());
})For a bit more performant match, you can use an optionally repeated group:
\w+(?:\s*\|+\s*\w+\s*)*$
Explanation
\w+ Match 1+ word chars(?: Non capture group to repeat as a whole
\s*\|+\s*\w+\s* Match 1 or more pipes and word chars between optional whitspace cars)* Optionally repeat$ End of stringSee a regex demo.
const names = [
'COMMENT — CODE | COUNTRY | DATE | TARGET',
'CODE| COUNTRY | DATE |TARGET',
'CODE|| COUNTRY| DATE |TARGET',
'COMMENT 1 — COMMENT 2 — CODE | COUNTRY | DATE | TARGET',
];
const regex = /\w+(?:\s*\|+\s*\w+\s*)*$/;
names.forEach(s => {
const m = s.match(regex);
if (m) {
console.log(m[0])
}
})