Javascript isset : Variable handling : PHP functions in JavaScript JAVASCRIPT TUTORIALS

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Javascript isset


Example 1

Running
1.isset( undefined, true);

Could return
1.false
Example 2

Running
1.isset( 'Kevin van Zonneveld' );

Could return
1.true 
function isset(  ) {
    // !No description available for isset. @php.js developers: Please update the function summary text file.
    // 
    // version: 810.114
    // discuss at: http://phpjs.org/functions/isset
    // +   original by: Kevin van Zonneveld (http://kevin.vanzonneveld.net)
    // +   improved by: FremyCompany
    // +   improved by: Onno Marsman
    // *     example 1: isset( undefined, true);
    // *     returns 1: false
    // *     example 2: isset( 'Kevin van Zonneveld' );
    // *     returns 2: true
    
    var a=arguments; var l=a.length; var i=0;
    
    if (l==0) { 
        throw new Error('Empty isset'); 
    }
    
    while (i!=l) {
        if (typeof(a[i])=='undefined' || a[i]===null) { 
            return false; 
        } else { 
            i++; 
        }
    }
    return true;
}


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