Not sure if I phrase the question correctly so here is an example
let string = "Test text ab/c test
Test t/est
### Test/
Test t/test
Test test"
I'm looking to remove / from only line that contains ### in it so it ends up like this:
Test text ab/c test
Test t/est
### Test
Test t/test
Test test
I assume I can use
mystring.replace(/\/g, '')
But how do I specify that it needs to remove \ only in the line with ###
You can split on newlines and then join them back again.
let string = `Test text ab/c test
Test t/est
### Test/
Test t/test
Test test
Test// ### test /
`
const parts = string.split("\n")
.map(s => s.includes("###") ? s.replace(/\//g, '') : s)
.join("\n");
console.log(parts);You can use
string.replace(/(?<=###.*)\/|\/(?=.*###)/g, '')
The (?<=###.*)\/|\/(?=.*###) regex matches a / char that is either preceded with ### and any zero or more non-line break chars, or followed with zero or more non-line break chars and then ###.
See this JavaScript demo:
let string = "Test text ab/c test\nTest t/est\n### /T/e/s/t/\nTest t/test\nTest test"
console.log(string.replace(/(?<=###.*)\/|\/(?=.*###)/g, ''))Another solution: split the stirng into lines, then map the resulting array and remove all / chars in the items that includes the ### substring, and then join the string back:
let string = "Test text ab/c test\nTest t/est\n### /T/e/s/t/\nTest t/test\nTest test"
console.log( string.split("\n").map(line => line.indexOf('###') > -1 ? line.replace(/\//g, '') : line).join("\n") ).replace() the whole segment then return everything but \/ (the \ is prefixed to / in order to escape it.
const str = `
Test text ab/c test
Test t/est
### Test/
Test t/test
Test test`;
const rgx = /(###.+)\//gm;
const sub = `$1`;
console.log(str.replace(rgx, sub));