You could extend the String object with your own function that does what you need (useful if there’s ever missing functionality):
String.prototype.replaceArray = function(find, replace) {
var replaceString = this;
for (var i = 0; i < find.length; i++) {
replaceString = replaceString.replace(find[i], replace[i]);
}
return replaceString;
};
For global replace you could use regex:
String.prototype.replaceArray = function(find, replace) {
var replaceString = this;
var regex;
for (var i = 0; i < find.length; i++) {
regex = new RegExp(find[i], "g");
replaceString = replaceString.replace(regex, replace[i]);
}
return replaceString;
};
To use the function it’d be similar to your PHP example:
var textarea = $(this).val();
var find = ["<", ">", "\n"];
var replace = ["<", ">", "<br/>"];
textarea = textarea.replaceArray(find, replace);