promise then failure catch

(new Promise(function(resolve, reject) {
    resolve('aa');
})).then(val => { console.log(val); throw new Error('aaa');}).catch((err)=> console.log('err' + err));

aa
errError: aaa

(new Promise(function(resolve, reject) {
    resolve('aa');
})).then(val => { 
    console.log(val); 
    throw new Error('aaa');
}).then((a)=>a, (val) => { console.log('reject'); }).catch((err)=> console.log('err' + err));

aa
reject

(new Promise(function(resolve, reject) {
    resolve('aa');
})).then(val => { 
    console.log(val); 
    throw new Error('aaa');
}).then((a)=>a).catch((err)=> console.log('err' + err));

aa
errError: aaa