bootstrap 4 div centro
<div class="d-flex justify-content-start">...</div>
<div class="d-flex justify-content-end">...</div>
<div class="d-flex justify-content-center">...</div>
<div class="d-flex justify-content-between">...</div>
<div class="d-flex justify-content-around">...</div>
contenido de bootstrap col center
<div class="row">
<div class="col-4 d-flex justify-content-center text-center">
// for image and text
</div>
</div>
ustify-contenido: flex-end
<div class="d-flex justify-content-end">...</div>
columna de la flexión de la exhibición
.container {
display: flex;
flex-direction: column;
}
flex wrap bootstrap
<div class="d-flex flex-wrap">...</div>
columna de dirección de flexión bootstrap
d-flex flex-column
pantalla de arranque flex
<div class="d-flex">I'm a flexbox container!</div>
columna de dirección flex bootstrap 4
<div class="d-flex justify-content-start">...</div>
<div class="d-flex justify-content-end">...</div>
<div class="d-flex justify-content-center">...</div>
<div class="d-flex justify-content-between">...</div>
<div class="d-flex justify-content-around">...</div>