No. There are two types of dashes and they have different meaning. An em-dash (about as long as the letter m) is the longer of the two and sometimes just two regular dashes is a break in the current thought of the sentence. The en-dash is the shorter dash, and what you are usually used to.
Here is how we use the em-dash:
It was another dreary afternoon, with hardly a thing to do, I had wasted the first hour of the day counting the number of tiles — what is that noise I hear?
It can also be used for emphasis, but is often heard in a different tone or manner than the main form of speech.
The en-dash has a number of uses, usually to bring together words, such as a jack-o'-lantern.
You may be looking for the colon:
Kids always say to their classmates: dishes cooked by their own mothers are the best in the world.
The dash can denote speech, usually in novels.
Mary was quite disturbed by the children in her class.
— What is your problem Mary? Why do you always wash your dishes?
— I'm a responsible young lady, and I will wash them as I please