How Can I mask all the digits that the user to input, dynamically?
Scenario 1: User input: 1234 5678 9123 4414 Output: xxxx xxxx xxxx 4414
Scenario 2: User input: 12345678 8234245 Output: xxxxxxxx xxx4245
Scenario 3: User input: 12 345678911 Output: xx xxxxx8911
What I have is a fix only and it is static, How can I make my code to be dynamic? so that I can lessen my if else statement?
function hideMask(num) {
var regExp = /[a-zA-Z]/g;
if(regExp.test(num)){
return null;
} else {
if(num.replace(/\s/g, '').length == 16){ // 16 digit
mask = num.substring(num.length - 14).replace(/\d/g,"x");
unmaskCardNumber = num.substring(14, 19);
return(mask + unmaskCardNumber);
}else if(num.replace(/\s/g, '').length == 18){ //18 digit
mask = num.substring(0,15).replace(/\d/g,"x");
unmaskCardNumber = num.substring(15, 19);
return(mask + unmaskCardNumber);
}else{
return null;
}
}
}
You can easily achieve the result using split, reverse and map
function mask(s) {
let count = 0;
return s
.split("")
.reverse()
.map((n, i) => (!n.match(/\d/) ? n : count < 4 ? (count++, n) : "x"))
.reverse()
.join("");
}
function mask(s) {
let count = 0;
return s
.split("")
.reverse()
.map((n, i) => {
if (!n.match(/\d/)) return n;
else {
return count < 4 ? (count++, n) : "x";
}
})
.reverse()
.join("");
}
console.log(mask("1234 5678 9123 4414"));
console.log(mask("12345678 8234245"));
console.log(mask("12 345678911"));
console.log(mask("12 345678 9 1 1")); // CORNER CASEYou can even skip reverse step if you use reduceRight as:
function mask(s) {
let count = 0;
return s
.split("")
.reduceRight((acc, n, i) => {
acc.push(!n.match(/\d/) ? n : count < 4 ? (count++, n) : "x");
return acc;
}, [])
.reverse()
.join("");
}
function mask(s) {
let count = 0;
return s
.split("")
.reduceRight((acc, n, i) => {
acc.push(!n.match(/\d/) ? n : count < 4 ? (count++, n) : "x");
return acc;
}, [])
.reverse()
.join("");
}
console.log(mask("1234 5678 9123 4414"));
console.log(mask("12345678 8234245"));
console.log(mask("12 345678 9 1 1"));I would go about it, using slice, and replace: First replace all alphanumeric characters in the string, bar the last four with 'x', and append the last four from before:
function mask(input) {
return input
.slice(0, input.length - 4)
.replace(/([a-zA-Z0-9])/g, 'x') + input.slice(-4)
}
console.log(mask('abcd efgh 1234 5678'))