lib/xlsx-to-json.js
function isBoolean(value) {

    if (typeof(value) == "undefined") {
        return false;
    }

    if (typeof value === 'boolean') {
        return true;
    };

    var b = value.toString().trim().toLowerCase();

    return b === 'true' || b === 'false';
}
function isBoolean(value) {

    if (typeof(value) == "undefined") {
        return false;
    }

    if (typeof value === 'boolean') {
        return true;
    };

    var b = value.toString().trim().toLowerCase();

    return b === 'true' || b === 'false';
}
function isBoolean ( value ) { if ( typeof ( value ) == "undefined" ) { return false ; } if ( typeof value === 'boolean' ) { return true ; } ; var b = value . toString ( ) . trim ( ) . toLowerCase ( ) ; return b === 'true' || b === 'false' ; }
boolean type check.
boolean type check .