I want to remove all numeric values from a string But only if the string contains at least one letter.
How can I do this in JavaScript?
For e.g.
var s = "asd23asd"
Then result must be asdasd
However if
var s = "123123"
Then result must be 123123 as the string does not have any letters.
function filter(string){
var result = string.replace(/\d/g,'')
return result || string;
}
or directly
var newString = string.replace(/\d/g,'') || string;
Why || works
the || and & are conditionals operators and sure that you used in if, while ...
If you do somethin like
var c1 = false, c2 = true, c3= false, c4 = true;
if( c1 || c2 || c3 || c4) {
}
This evaluation will stop in the first moment that is valid or invalid.
this mind that the evaluation stop in c2 this mind that is more fast (true || false) than (false || true)
At this point we can add another concept, the operator return always the last element in the evaluation
(false || 'hey' || true) return 'hey', remember in JS 'hey' is true but '' is false
Interesting examples:
var example = {
'value' : {
'sub_value' : 4
}
}
var test = example && example.value && example.value.sub_value;
console.log(test) //4
var test_2 = example && example.no_exist && example.no_exist.sub_value;
console.log(test_2) //undefined
var test_3 = example.valno_existue.sub_value; //exception
function test_function(value){
value = value || 4; //you can expecify default values
}
You can try this. First check if the word contains any alphabet, if yes then replace.
var s = "asd23asd";
if(/\w+/.test(s))
s = s.replace(/\d+/g, '');
([a-zA-Z]+)\d+|\d+(?=[a-zA-Z]+)
You can try this.Replace by $1.See demo.
Javascript Code
var txt='asd23ASd3';
if(parseInt(txt))
var parsed=txt;
else
var parsed=txt.replace ( /[^a-zA-Z]/g, '');
console.log(parsed)
-1should remain-1, or+2remain+2. What abouta+2should it beaora+and what about whitespace or characters from other alphabets likeå,äorö, or characters_!:;,and so on?