I have the following string with placeholders
'test {{1}} this {{2}} {{3}}'
these placeholders later should be replaced in same order by the values from input fields
['now', 'code', 'block']
so the final string looks like this
'test now this code block'
what’s the best approach here?
>Solution :
You can use .replace() on your string with a regular expression to match the digits between the {{ and }} characters. Then, using the replacement function, which will fire for each digit that is matched, you can return the new value to replace the {{N}} occurrence with, which will be the value of the current digit -1 from your array of values.
const arr = ['now', 'code', 'block'];
const str = 'test {{1}} this {{2}} {{3}}';
const res = str.replace(/{{([^}}]+)}}/g, (_, d) => arr[d-1]);
console.log(res);Regex explanation for /{{([^}}]+)}}/g:
{{– Match the literal characters{{in your string([^}}]+)– Continue matching one or more characters that aren’t}}and capture them in a group (the(and)forms a capturing group for your digit)}}– match the literal}}characters/g– The global flag means match all occurrences of this pattern throughout your string.
In this case, the first argument to the replacement function is the entire match itself (ie: {{N}}) which we ignore with _, and the second argument is the capturing group we formed that has your digit.