a=new String("Hello");
a[0]==="H" //true
a[0]="J"
a[0]==="J" //false
a[0]==="H" //true
Does this mean I can only use Strings as arrays of char's by .split("") and then .join("")?
ANSWER: Yes, in Javascript strings are readonly (aka immutable) This question is answered here at:
Strings are immutable, so yes. a should be reassigned if you want to change the string. You can also use slice: a = 'j'+a.slice(1), or a replace: a = a.replace(/^h/i,'j').
You could create a custom mutable String object, something like this experiment (esp. see method replaceCharAt).
Thats correct.
You can of course build a function to handle this for you.
See this SO Post for different examples of this:
How do I replace a character at a particular index in JavaScript?
If it is necessary to be able to perform manipulations on your string as if it were an array or chars, that you perhaps create some prototypes:
String.prototype.splice = function(start,length,insert) {
var a = this.slice(0, start);
var b = this.slice(start+length, this.length);
if (!insert) {insert = "";};
return new String(a + insert + b);
};
String.prototype.push = function(insert) {
var a = this
return new String(a + insert);
};
String.prototype.pop = function() {
return new String(this.slice(0,this.length-1));
};
String.prototype.concat = function() {
if (arguments.length > 0) {
var string = "";
for (var i=0; i < arguments.length; i++) {
string += arguments[i];
};
return new String(this + string);
};
};
String.prototype.sort = function(funct) {
var arr = [];
var string = "";
for (var i=0; i < this.length; i++) {
arr.push(this[i]);
};
arr.sort(funct);
for (var i=0; i < arr.length; i++) {
string += arr[i];
};
return new String(string);
};
var a = new String("hello");
var b = a.splice(1,1,"b");
var c = a.pop();
var d = a.concat(b,c);
var e = a.sort();
returns hello, hbllo, hell, hellohbllohell, ehllo
wouldn't the .valueOf() method of the Strings prototype return its primitive value ? Like,
Basically string in javascript are differentiated by two types one is primitive and another is object . String objects are character sequences .
You can use primitive type of string .
var x = "hello";
console.log(x);
output : "hello"
x = "j"+x.substring(1);
console.log(x);
output : "jello";
Or use
var x = new String("hello");
console.log(x.toString());
x = "j"+x.substring(1);
