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it is better to check with isFinite() rather than typeof or isNAN()
check this:
var name="somename",trickyName="123", invalidName="123abc";
typeof name == typeof trickyName == typeof invalidName == "string"
isNAN(name)==true
isNAN(trickyName)==false
isNAN(invalidName)==true
where:
isFinite(name) == false
isFinite(trickyName)== true
isFinite(invalidName)== true
so we can do:
if(!isFinite(/*any string*/))
console.log("it is string type for sure")
notice that:
isFinite("asd123")==false
isNAN("asd123")==true
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// Example 1:
const string = "Hello world!";
n = string.includes("world");
// n is equal to true in Example 1
// Example 2:
const string = "Hello world!, I am Kavyansh";
n = string.includes("I am Aman");
// n is equal to false in Example 2
// Note: the .includes method is case sensitive
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function isString(value) {
if (typeof value === "string") {
return true;
}
return false;
}
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function isString(variable) {
return typeof variable === 'string';
}
// Example usage:
console.log(isString('Hello')); // true
console.log(isString(123)); // false
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const str = "Hello World";
const searchString = "World";
if (str.includes(searchString)) {
console.log("String exists!");
} else {
console.log("String does not exist!");
}
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function isString(x) {
return Object.prototype.toString.call(x) === "[object String]"
}
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let eventValue = event.target.value;
if (/^\d+$/.test(eventValue)) {
eventValue = parseInt(eventValue, 10);
}
//If value is a string, it converts to integer.
//Otherwise it remains integer.