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var value = "test string"
console.log(typeof value === "string")
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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 = 'This is my example string!';
const substr = 'my';
console.log(str.includes(substr));
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var booleanValue = true;
var numericalValue = 354;
var stringValue = "This is a String";
var stringObject = new String( "This is a String Object" );
alert(typeof booleanValue) // displays "boolean"
alert(typeof numericalValue) // displays "number"
alert(typeof stringValue) // displays "string"
alert(typeof stringObject) // displays "object"
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if (typeof a_string === 'string') {
// this is a string
}
if (typeof myVar === 'integer'){
//I am indeed an integer
}
if (typeof myVar === 'boolean'){
//I am indeed a boolean
}
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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.
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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