display: flex in css meaning code example

Example 1: display flex

.container {
     display: flex;
     align-items: center;
     justify-content: center;
}

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Example 2: display flex css

.class {
  display: flex;
}

/* use display: flex to turn CSS element into a flexbox */

Example 3: css flex

.item {
  flex-basis:  | auto; /* default auto */
}