If and For in Wolfram Mathematica (with examples)

IF Condition in Wolfram Mathematica

The syntax is as follows

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If[condition, what to do if true, what to do if false]

Some examples

Example 1. Simple command

x
x = -3;
If[x<0, -x, x]
3

Example 2. If condition in a function

abs[x_]:=If[x<0, -x, x]
abs/@{-3, 2, 0, -2}
{3, 2, 0, 2}

 

For in Wolfram Mathematica

The syntax is as follows

For[start, test, inc, what to do]

Some examples

Example 1. Simple Loop

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For[i=0, i<4, i++, Print[i]]
0
1
2
3

Example 2. Another simple loop

For[i=10, i>0, i--, Print[i]]
10
9
8
7
6
5
4
3
2
1

Example 3. Print list

a={10, 3, 9, 2}
For[i=1,i<5,i++,Print[a[[i]]]]
10
3
9
2