JavaScript: Convert Roman Numeral to Integer
JavaScript Math: Exercise-22 with Solution
Write a JavaScript function that converts Roman numerals to integers.
Sample Solution:-
HTML Code:
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>Write a JavaScript function that Convert Roman Numeral to Integer</title>
</head>
<body>
</body>
</html>
JavaScript Code:
function roman_to_Int(str1) {
if(str1 == null) return -1;
var num = char_to_int(str1.charAt(0));
var pre, curr;
for(var i = 1; i < str1.length; i++){
curr = char_to_int(str1.charAt(i));
pre = char_to_int(str1.charAt(i-1));
if(curr <= pre){
num += curr;
} else {
num = num - pre*2 + curr;
}
}
return num;
}
function char_to_int(c){
switch (c){
case 'I': return 1;
case 'V': return 5;
case 'X': return 10;
case 'L': return 50;
case 'C': return 100;
case 'D': return 500;
case 'M': return 1000;
default: return -1;
}
}
console.log(roman_to_Int('XXVI'));
console.log(roman_to_Int('CI'));
Sample Output:
26 101
Pictorial Presentation:
Flowchart:

Live Demo:
See the Pen javascript-math-exercise-22 by w3resource (@w3resource) on CodePen.
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