API URL не поддерживается в IE11, что означает, что эти строки завершатся сбоем и приведут пользователя к предложению else {}
:
var visitor = new URL(location);
var newvisitor = visitor.searchParams.get("v");
Редактировать: Вот несколько полезных проверок на равенство для выполнения в жестко запрограммированных тестах.
let newvisitor = 0; // <-- var is fine, too, but not const
console.log('==, testing number 0 against string equality')
if (newvisitor == '0') {
console.log("New visitor.")
} else {
console.log("Returning visitor.")
}
console.log('==, testing number 0 against numeric equality')
if (newvisitor == 0) {
console.log("New visitor.")
} else {
console.log("Returning visitor.")
}
newvisitor = "0";
console.log('==, testing string "0" against string equality')
if (newvisitor == '0') {
console.log("New visitor.")
} else {
console.log("Returning visitor.")
}
console.log('==, testing string "0" against numeric equality')
if (newvisitor == 0) {
console.log("New visitor.")
} else {
console.log("Returning visitor.")
}
newvisitor = 0;
console.log('===, testing number 0 against string equality')
if (newvisitor === '0') {
console.log("New visitor.")
} else {
console.log("Returning visitor.")
}
console.log('===, testing number 0 against numeric equality')
if (newvisitor === 0) {
console.log("New visitor.")
} else {
console.log("Returning visitor.")
}
newvisitor = "0";
console.log('===, testing string "0" against string equality')
if (newvisitor === '0') {
console.log("New visitor.")
} else {
console.log("Returning visitor.")
}
console.log('===, testing string "0" against numeric equality')
if (newvisitor === 0) {
console.log("New visitor.")
} else {
console.log("Returning visitor.")
}
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