sub
sub(pattern, replacement[, count = 1]) -> string
Returns a string with the first count
occurrences of pattern
replaced by either a regular string, the returned value of a function or a Template
string. pattern
can be a string or a regular expression.
Unlike String#gsub
, String#sub
takes a third optional parameter which specifies the number of occurrences of the pattern which will be replaced. If not specified, it will default to 1.
Apart from that, String#sub
works just like String#gsub
. Please refer to it for a complete explanation.
Examples
var fruits = 'apple pear orange';
fruits.sub(' ', ', ');
// -> 'apple, pear orange'
fruits.sub(' ', ', ', 1);
// -> 'apple, pear orange'
fruits.sub(' ', ', ', 2);
// -> 'apple, pear, orange'
fruits.sub(/\w+/, function(match){return match[0].capitalize() + ','}, 2);
// -> 'Apple, Pear, orange'
var markdown = '![a pear](/img/pear.jpg) ![an orange](/img/orange.jpg)';
markdown.sub(/!\[(.*?)\]\((.*?)\)/, function(match){
return '<img alt="' + match[1] + '" src="' + match[2] + '" />';
});
// -> '<img alt="a pear" src="/img/pear.jpg" /> ![an orange](/img/orange.jpg)'
markdown.sub(/!\[(.*?)\]\((.*?)\)/, '<img alt="#{1}" src="#{2}" />');
// -> '<img alt="a pear" src="/img/pear.jpg" /> ![an orange](/img/orange.jpg)'
Note
Do not use the "g"
flag on the regex as this will create an infinite loop.