how to check if a string is an integer javascript

// native returns true if the variable does NOT contain a valid number
isNaN(num)

// can be wrapped for making simple and readable
function isNumeric(num){
  return !isNaN(num)
}

isNumeric(123)         // true
isNumeric('123')       // true
isNumeric('1e10000')   // true (This translates to Infinity, which is a number)
isNumeric('foo')       // false
isNumeric('10px')      // false

4.5
2
Lakesare 90 points

                                    if (typeof myVar === 'string'){<br/>    //I am indeed a string<br/>}

4.5 (2 Votes)
0
4.43
7

                                    function isNumeric(str) {

	// Check if input is string
	if (typeof str != &quot;string&quot;)
    	return false

	// Use type coercion to parse the _entirety_ of the string
    // (`parseFloat` alone does not do this).
	// Also ensure that the strings whitespaces fail
	return !isNaN(str) &amp;&amp; 
		!isNaN(parseFloat(str)) 
}

4.43 (7 Votes)
0
3.78
9

                                    isNaN(num)         // returns true if the variable does NOT contain a valid number

3.78 (9 Votes)
0
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