I wrote the function that tokenizes arithmetic string expression into an array of tokens, such as numbers and operators. Everything's fine but I get a weird results when dealing with strings containing "10". Here's the code:
function tokenizeString(expressionString) {
const tokenArray = [];
let token = "";
for (let i = 0; i < expressionString.length; i++) {
if (parseInt(expressionString[i])) {
token += expressionString[i];
} else {
tokenArray.push(parseInt(token));
token = "";
tokenArray.push(expressionString[i]);
}
}
if (token !== "") {
tokenArray.push(parseInt(token));
}
return tokenArray;
}
console.log(tokenizeString("14+2/8")); // [14, "+", 2, "/", 8]
console.log(tokenizeString("10+1")); // [1, '0', NaN, '-', 3] ??For now I can't come up with an idea, why this happens.
Instead of parseInt in the
if(parseInt(expressionString[i])){}
you could use isNaN() to check if the string is number or not
isNaN() returns true if not a number so your if would
be
if (!isNaN(expressionString[i])){}
function tokenizeString(expressionString) {
const tokenArray = [];
let token = "";
for (let i = 0; i < expressionString.length; i++) {
if (!isNaN(expressionString[i])) {
token += expressionString[i];
} else {
tokenArray.push(parseInt(token));
token = "";
tokenArray.push(expressionString[i]);
}
}
if (token !== "") {
tokenArray.push(parseInt(token));
}
return tokenArray;
}
console.log(tokenizeString("14+2/8")); // [14, "+", 2, "/", 8]
console.log(tokenizeString("10+1")); // [10, '+', 1] ??