CODEWITHSUNDEEP
javascriptreactjsregex
tinytree
tinytree

Reputation: 1099

Modify numbers in large string

I'm trying to modify certain numbers inside a large string, which start with an #.

So for example I have this String:

var text = "#41 = AXIS2_PLACEMENT_3D ( 'NONE', #3200, #1543, #6232 ) ;
#42 = EDGE_CURVE ( 'NONE', #180, #933, #1234, .T. ) ;"

Then I want to add a fixed number to every number after an "#" e.g. add 100 to every number to get this:

text = "#141 = AXIS2_PLACEMENT_3D ( 'NONE', #3300, #1643, #6332 ) ;
#142 = EDGE_CURVE ( 'NONE', #280, #1033, #1334, .T. ) ;"

I got this far with regex:

const offset = 100;
const matchingExpression = /\#(\d+)/ig;
text = text.replaceAll(matchingExpression, "#" + //old value + offset);

I now can replace all numbers that start with an "#". But how do I get the old values?

I'm not very familiar with regex and don't know if this approach is the way to go. Hope you can help me.

Thanks in regard

Upvotes: 2

Views: 51

Answers (2)

Roko C. Buljan
Roko C. Buljan

Reputation: 206668

Use the second argument (function callback) of the String.prototype.replace method:

const add100 = (text) => text.replace(/#(\d+)/gm, (m, n) => `#${+n + 100}`);


const text = `#41 = AXIS2_PLACEMENT_3D ( 'NONE', #3200, #1543, #6232 ) ;
#42 = EDGE_CURVE ( 'NONE', #180, #933, #1234, .T. ) ;`;

console.log(add100(text));

Upvotes: 1

Marco
Marco

Reputation: 7277

You can use String.replace like this:

const offset = 100;
const matchingExpression = /\#(\d+)/ig;

text = text.replace(matchingExpression, function(match) {
    return "#" + (parseInt(match.slice(1)) + offset)
});

Upvotes: 0

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