Preview:
function AdditivePersistence(num) { 

    var sum, loop = 0;
    var val1 = num.toString(10).split("").map(function(t){return parseInt(t)});
   
    while (val1.length > 1) {
        sum = 0;
        val1.forEach( function(number) {
            sum = sum + number;
        });
        
        val1 = sum.toString(10).split("").map(function(t){return parseInt(t)});
        loop++;
    } 
    
    return loop;
         
}
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